{"id":8274,"date":"2022-03-09T12:14:57","date_gmt":"2022-03-09T06:44:57","guid":{"rendered":"https:\/\/envisionmathanswerkey.com\/?p=8274"},"modified":"2022-03-15T10:35:28","modified_gmt":"2022-03-15T05:05:28","slug":"envision-math-common-core-grade-3-answer-key-topic-9-fluently-add-and-subtract-within-1000","status":"publish","type":"post","link":"https:\/\/envisionmathanswerkey.com\/envision-math-common-core-grade-3-answer-key-topic-9-fluently-add-and-subtract-within-1000\/","title":{"rendered":"enVision Math Common Core Grade 3 Answer Key Topic 9 Fluently Add and Subtract within 1,000"},"content":{"rendered":"

Go through the\u00a0enVision Math Common Core Grade 3 Answer Key<\/a>\u00a0Topic 9 Fluently Add and Subtract within 1,000<\/strong>\u00a0regularly and improve your accuracy in solving questions.<\/p>\n

enVision Math Common Core 3rd Grade Answers Key Topic 9 Fluently Add and Subtract within 1,000<\/h2>\n

Essential Question:<\/strong> What are the procedures for adding and subtracting whole numbers?<\/p>\n

\"Envision
\nenVision STEM Project: Changing Environments<\/strong>
\nDo Research<\/strong> Forest fires destroy, but they also make room for new growth. Use the Internet or other sources to find information about forest fires. Describe the effect of forest fires on plant and animal populations.
\nJournal: Write a Report<\/strong> Include data with numbers for the population you researched. Also in your report:<\/p>\n

    \n
  • Choose a kind of animal or plant. Tell how a change in the environment can affect the number of animals or plants.<\/li>\n
  • Write and solve an addition and a subtraction problem using your data.<\/li>\n<\/ul>\n

    Review What You Know<\/strong><\/p>\n

    Vocabulary<\/strong><\/p>\n

    Choose the best term from the box. Write it on the blank.<\/p>\n

    \u2022 Associative Property of Addition
    \n\u2022 Commutative Property of Addition
    \n\u2022 compatible numbers
    \n\u2022 inverse operations<\/p>\n

    Question 1.
    \n___ are easy to add or subtract mentally.
    \nAnswer:
    \nCompatible numbers are pairs of numbers that are easy to add, subtract, multiply, or divide mentally.
    \nThus, Compatible numbers are easy to add or subtract mentally.<\/p>\n

    Question 2.
    \nAccording to the _______, the grouping of addends can be changed, and the sum will remain the same.
    \nAnswer:
    \nThe commutative property of addition says that changing the order of addends does not change the sum.
    \nSo, According to the commutative property of addition, the grouping of addends can be changed, and the sum will remain the same.<\/p>\n

    Question 3.
    \nAddition and subtraction are ___
    \nAnswer:
    \nInverse operations are pairs of mathematical manipulations in which one operation undoes the action of the other.
    \nThus Addition and subtraction are inverse operations.<\/p>\n

    Rounding<\/strong><\/p>\n

    Round each number to the nearest ten.<\/p>\n

    Question 4.
    \n57
    \nAnswer:
    \nIf the number you are rounding is followed by 5, 6, 7, 8, or 9, round the number up.
    \nHere 7 is greater than 5.
    \nSo, 57 round to the nearest ten is 60.<\/p>\n

    Question 5.
    \n241
    \nAnswer:
    \nIf the number you are rounding is followed by 0, 1, 2, 3, or 4, round the number down.
    \nSo, 241 round to the nearest ten is 240.<\/p>\n

    Question 6.
    \n495
    \nAnswer:
    \nIf the number you are rounding is followed by 5, 6, 7, 8, or 9, round the number up.
    \nThus 495 round to the nearest ten is 500.<\/p>\n

    Round each number to the nearest hundred.<\/p>\n

    Question 7.
    \n732
    \nAnswer:
    \nWhen rounding to the nearest hundred, look at the tens place of the number.
    \nIf the tens digit is 0, 1, 2, 3, or 4, you will round down to the previous hundred.
    \nIf that digit is 5, 6, 7, 8, or 9, you will round up to the next hundred.
    \nThus the number 732 to the nearest hundred is 700.<\/p>\n

    Question 8.
    \n81
    \nAnswer:
    \nWhen rounding to the nearest hundred, look at the tens place of the number.
    \nIf the tens digit is 0, 1, 2, 3, or 4, you will round down to the previous hundred.
    \nIf that digit is 5, 6, 7, 8, or 9, you will round up to the next hundred.
    \nThus the number 81 to the nearest hundred is 100.<\/p>\n

    Question 9.
    \n553
    \nAnswer:
    \nWhen rounding to the nearest hundred, look at the tens place of the number.
    \nIf the tens digit is 0, 1, 2, 3, or 4, you will round down to the previous hundred.
    \nIf that digit is 5, 6, 7, 8, or 9, you will round up to the next hundred.
    \nThus the number 553 to the nearest hundred is 600.<\/p>\n

    Estimating Sums<\/strong><\/p>\n

    Use compatible numbers to estimate each sum.<\/p>\n

    Question 10.
    \n27 + 12
    \nAnswer:
    \nCompatible numbers are pairs of numbers that are easy to add, subtract, multiply, or divide mentally.
    \nWrite 27 and 12 to the nearest ten.
    \nIf the number you are rounding is followed by 5, 6, 7, 8, or 9, round the number up.
    \nIf the number you are rounding is followed by 0, 1, 2, 3, or 4, round the number down.
    \n27 to the nearest ten is 30.
    \n12 to the nearest ten is 10.
    \n30 + 10 = 40
    \nThus the estimated sum is 40.<\/p>\n

    Question 11.
    \n133 + 102
    \nAnswer:
    \nCompatible numbers are pairs of numbers that are easy to add, subtract, multiply, or divide mentally.
    \nIf the number you are rounding is followed by 5, 6, 7, 8, or 9, round the number up.
    \nIf the number you are rounding is followed by 0, 1, 2, 3, or 4, round the number down.
    \n133 to the nearest ten is 130.
    \n102 to the nearest ten is 100.
    \n130 + 100 = 230
    \nThus the estimated sum is 230.<\/p>\n

    Question 12.
    \n504 + 345
    \nAnswer:
    \nCompatible numbers are pairs of numbers that are easy to add, subtract, multiply, or divide mentally.
    \nWhen rounding to the nearest hundred, look at the tens place of the number.
    \nIf the tens digit is 0, 1, 2, 3, or 4, you will round down to the previous hundred.
    \nIf that digit is 5, 6, 7, 8, or 9, you will round up to the next hundred.
    \nThus the number 504 to the nearest hundred is 500.
    \nThus the number 345 to the nearest hundred is 300.
    \n500 + 300 = 800
    \nThus the estimated sum is 800.<\/p>\n

    Question 13.
    \n52 + 870
    \nAnswer:
    \nCompatible numbers are pairs of numbers that are easy to add, subtract, multiply, or divide mentally.
    \nWhen rounding to the nearest hundred, look at the tens place of the number.
    \nIf the tens digit is 0, 1, 2, 3, or 4, you will round down to the previous hundred.
    \nIf that digit is 5, 6, 7, 8, or 9, you will round up to the next hundred.
    \nIf the number you are rounding is followed by 0, 1, 2, 3, or 4, round the number down.
    \nThus the number 52 to the nearest ten is 50.
    \nThus the number 870 to the nearest hundred is 900.
    \n900 + 50 = 950
    \nThus the estimated sum is 950.<\/p>\n

    Question 14.
    \n293 + 278
    \nAnswer:
    \nCompatible numbers are pairs of numbers that are easy to add, subtract, multiply, or divide mentally.
    \nWhen rounding to the nearest hundred, look at the tens place of the number.
    \nIf the tens digit is 0, 1, 2, 3, or 4, you will round down to the previous hundred.
    \nIf that digit is 5, 6, 7, 8, or 9, you will round up to the next hundred.
    \nIf the number you are rounding is followed by 0, 1, 2, 3, or 4, round the number down.
    \nThus the number 293 to the nearest hundred is 300.
    \nThus the number 278 to the nearest hundred is 300.
    \n300 + 300 = 600
    \nThus the estimated sum is 600.<\/p>\n

    Question 15.
    \n119 + 426
    \nAnswer:
    \nCompatible numbers are pairs of numbers that are easy to add, subtract, multiply, or divide mentally.
    \nWhen rounding to the nearest hundred, look at the tens place of the number.
    \nIf the tens digit is 0, 1, 2, 3, or 4, you will round down to the previous hundred.
    \nIf that digit is 5, 6, 7, 8, or 9, you will round up to the next hundred.
    \nIf the number you are rounding is followed by 0, 1, 2, 3, or 4, round the number down.
    \nThus the number 119 to the nearest hundred is 100.
    \nThus the number 426 to the nearest hundred is 400.
    \n100 + 400 = 500
    \nThus the estimated sum is 500.<\/p>\n

    Estimating Differences<\/strong><\/p>\n

    Question 16.
    \nTony and Kim play a video game. Tony scores 512 points. Kim scores 768 points. About how many more points does Kim score than Tony? Which estimation method did you use?
    \nAnswer:
    \nGiven,
    \nTony and Kim play a video game. Tony scores 512 points. Kim scores 768 points.
    \n768 – 512
    \nWrite the nearest hundred values for both the numbers to estimate the sum.
    \nWhen rounding to the nearest hundred, look at the tens place of the number.
    \nIf the tens digit is 0, 1, 2, 3, or 4, you will round down to the previous hundred.
    \nIf that digit is 5, 6, 7, 8, or 9, you will round up to the next hundred.
    \nThus the number 512 to the nearest hundred is 500.
    \nThus the number 768 to the nearest hundred is 800.
    \n800 – 500 = 300
    \nThus Kim scores nearly .00 points than Tony.<\/p>\n

    Question 17.
    \nWhich number sentence shows the most reasonable estimate for
    \nA. 425 \u2013 250 = 175
    \nB. 500 \u2013 200 = 300
    \nC. 400 \u2013 300 = 100
    \nD. 470 \u2013 230 = 240
    \nAnswer: 500 \u2013 200 = 300<\/p>\n

    Pick a Project<\/strong><\/p>\n

    PROJECT 9A<\/strong>
    \n\"Envision
    \nHow do you know which is the tallest building?
    \nProject: Research the Heights of Tall Buildings<\/p>\n

    PROJECT 9B<\/strong>
    \nHow can you record what you bought over time? Project: Create an Addition Skit
    \n\"Envision<\/p>\n

    PROJECT 9C<\/strong>
    \nHow long before the space shuttle launches?
    \nProject: Write a Report About Your Vacation
    \n\"Envision<\/p>\n

    3-ACT MATH PREVIEW<\/strong><\/p>\n

    Math Modeling<\/strong>
    \nFun Raiser<\/strong><\/p>\n

    \"Envision
    \nBefore watching the video, think: When a school needs extra money for a field trip or a student club, it might hold a fundraiser to collect that money.
    \nThis check is SO BIG, we must have collected a ton of money!<\/p>\n

    Lesson 9.1 Use Partial Sums to Add<\/h3>\n

    Activity<\/strong><\/p>\n

    Solve & Share<\/strong>
    \nThere are 2 bins of oranges. One bin has 378 oranges. The other bin has 243 oranges. Find the sum of 378 + 243. Think about place value.<\/p>\n

    You can use structure. You can break apart the problem to show each of the addends in expanded form.
    \n\"Envision<\/p>\n

    Look Back!<\/strong> Adam has 9 bags of oranges with 8 oranges in each. He also has a bin with 325 oranges. How many oranges does Adam have in all? Think about how you can use place value or other tools to help solve the problem. Explain your solution, what tool you used, and why.<\/p>\n

    Essential Question<\/strong> How Can You Break Apart Addition Problems to Solve?<\/p>\n

    Visual Learning Bridge<\/strong><\/p>\n

    A.<\/strong>
    \nMargot counted 243 manatees one year and 179 manatees the next. How many manatees did Margot count all together?
    \n\"Envision<\/p>\n

    B.<\/strong>
    \nYou can estimate and then use place value to add the numbers.
    \n\"Envision
    \n\"Envision
    \nThe sum is about 400 manatees.
    \n\"Envision<\/p>\n

    C.<\/strong>
    \nOne Way<\/strong>
    \nAdd each place value. Start with hundreds.
    \n\"Envision
    \n300, 110, and 12 are partial sums.
    \n243 + 179 = 422 manatees<\/p>\n

    D.<\/strong>
    \nAnother Way<\/strong>
    \nAdd each place value. Start with ones.
    \n\"Envision
    \nWhen you add by place value, you add the hundreds, the tens, and the ones.
    \n\"Envision
    \n243 + 179 = 422 manatees
    \n422 is close to the estimate of 400.
    \nSo, 422 is a reasonable sum.<\/p>\n

    Convince Me!<\/strong>
    \nCritique Reasoning<\/strong> Lexi used partial sums to complete the problem. Critique Lexi’s reasoning. Is her work correct? Explain.
    \n\"Envision<\/p>\n

    Guided Practices<\/strong><\/p>\n

    Do You Understand?<\/strong><\/p>\n

    Question 1.
    \nSuppose you were adding 527 + 405. What numbers would you combine when adding the tens? Why?
    \nAnswer:
    \nWhen rounding to the nearest hundred, look at the tens place of the number.
    \nIf the tens digit is 0, 1, 2, 3, or 4, you will round down to the previous hundred.
    \nIf that digit is 5, 6, 7, 8, or 9, you will round up to the next hundred.
    \nAdd 3 to 527 = 530
    \n530
    \n410<\/span>
    \n940
    \nThus, It would be 3 because when you add it, it gets to be 932 and the tens place is 3.<\/p>\n

    Question 2.
    \nFind the error. Show how to find the correct answer.
    \n\"Envision
    \nAnswer:
    \nFirst round the numbers to the nearest hundred.
    \n237 to the nearest hundred is 200
    \n285 to the nearest hundred is 300
    \n200 + 300 = 500
    \nSo, the estimated answer is 500.<\/p>\n

    Do You Know How?<\/strong><\/p>\n

    In 3, estimate the sum. Use place-value blocks or drawings and partial sums to add.<\/p>\n

    Question 3.
    \n\"Envision
    \nAnswer:
    \nWhen rounding to the nearest hundred, look at the tens place of the number.
    \nIf the tens digit is 0, 1, 2, 3, or 4, you will round down to the previous hundred.
    \nIf that digit is 5, 6, 7, 8, or 9, you will round up to the next hundred.
    \n365 to the nearest hundred is 400
    \n422 to the nearest hundred is 400
    \n400 + 400 = 800
    \nSo, the estimated answer is 800.<\/p>\n

    Independent Practice<\/strong><\/p>\n

    Leveled Practice<\/strong> In 4-11, estimate each sum. Use place-value blocks or drawings and partial sums to add.<\/p>\n

    Question 4.
    \n\"Envision
    \nAnswer:
    \nWhen rounding to the nearest hundred, look at the tens place of the number.
    \nIf the tens digit is 0, 1, 2, 3, or 4, you will round down to the previous hundred.
    \nIf that digit is 5, 6, 7, 8, or 9, you will round up to the next hundred.
    \n356 to the nearest hundred is 400
    \n123 to the nearest hundred is 100
    \n400 + 100 = 500
    \nSo, the estimated answer is 500.<\/p>\n

    Question 5.
    \n\"Envision
    \nAnswer:
    \n550 + 423 = 973
    \n973 is close to 1000.
    \nSo, the estimated sum is 1000.<\/p>\n

    Question 6.
    \n185 + 613
    \nAnswer:
    \n185 + 613 = 798
    \n798 is close to 800.
    \nSo, the estimated sum is 800.<\/p>\n

    Question 7.
    \n730 + 168
    \nAnswer:
    \n730 + 168 = 898
    \n898 is close to 900.
    \nSo, the estimated sum is 900.<\/p>\n

    Question 8.
    \n546 + 143
    \nAnswer:
    \n546 + 143 = 689
    \n689 is close to 700.
    \nSo, the estimated sum is 700.<\/p>\n

    Question 9.
    \n362 + 524
    \nAnswer:
    \n362 + 524 = 886
    \n886 is close to 900.
    \nSo, the estimated sum is 900.<\/p>\n

    Question 10.
    \n644 + 101
    \nAnswer:
    \n644 + 101 = 745
    \n745 is close to 700.
    \nSo, the estimated sum is 700.<\/p>\n

    Question 11.
    \n463 + 315
    \nAnswer:
    \n463 + 315 = 778
    \n778 is close to 800.
    \nSo, the estimated sum is 800.<\/p>\n

    Problem Solving<\/strong><\/p>\n

    Question 12.
    \nModel with Math<\/strong> John read a book with 377 pages. Jess read a book with 210 pages. How many pages did John and Jess read? Use place-value blocks and partial sums to solve. Draw a model to represent the problem.
    \nAnswer:
    \nGiven,
    \nJohn read a book with 377 pages. Jess read a book with 210 pages.
    \n377 + 210 = 587
    \n587 is close to 600.
    \nSo, the estimated sum is 600.<\/p>\n

    Question 13.
    \nExplain how the solids shown in Group A and Group B could have been sorted.
    \n\"Envision
    \nAnswer:<\/p>\n

    Question 14.
    \nHenry believes the sum of 275 + 313 is 598. Is Henry correct? Use place-value blocks or drawings and partial sums in your explanation.
    \n\"Envision
    \nAnswer:
    \nGiven,
    \nHenry believes the sum of 275 + 313 is 598.
    \nThe sum of 275 and 313 os 588.
    \nHenry is not correct.<\/p>\n

    Question 15.
    \nHigher Order Thinking<\/strong> A school cafeteria sold 255 lunches on Monday, 140 lunches on Tuesday, and 226 lunches on Wednesday. Did the cafeteria sell more lunches on Monday and Tuesday or on Tuesday and Wednesday? Use place value blocks or drawings to solve.
    \nAnswer:
    \nGiven,
    \nA school cafeteria sold 255 lunches on Monday, 140 lunches on Tuesday, and 226 lunches on Wednesday.
    \n225 + 140 = 365
    \n140 + 226 = 366
    \nThus cafeteria sells more lunches on Tuesday and Wednesday.<\/p>\n

    Assessment Practice<\/strong><\/p>\n

    Question 16.
    \nWhich shows breaking 622 + 247 apart by place value to find the sum?
    \nA. 600 + 200; 22 + 40; 2 + 7
    \nB. 600 + 300; 20 + 40; 2 + 7
    \nC. 600 + 200; 20 + 40; 2 + 7
    \nD. 600 + 200; 20 + 47; 2 + 7
    \nAnswer: A. 600 + 200; 22 + 40; 2 + 7<\/p>\n

    Question 17.
    \nBreak 331 + 516 apart by place value. Find the sum.
    \nA. 848
    \nB. 847
    \nC. 748
    \nD. 488
    \nAnswer:
    \n331 + 516 = 847
    \nThus the correct answer is option B.<\/p>\n

    Lesson 9.2 Use Regrouping to Add<\/h3>\n

    Activity<\/strong><\/p>\n

    Solve & Share<\/strong><\/p>\n

    Suppose a bus travels 276 miles on Monday and 248 miles on Tuesday. How many miles does the bus travel?<\/p>\n

    You can use appropriate tools, such as place-value blocks, to add larger numbers. What other strategies can you use to solve
    \nthis problem?
    \n\"Envision<\/p>\n

    Look Back!<\/strong> On Wednesday, the bus gets stuck in traffic. It travels 8 miles each hour for 8 hours. The bus needs to travel 600 miles total from Monday to Wednesday to make it to its destination. Does the bus make it to its destination? Why would it be a good idea to estimate first before you solve this problem?<\/p>\n

    Visual Learning Bridge<\/strong><\/p>\n

    Essential Question<\/strong>
    \nHow Can You Use Regrouping to Solve Addition Problems?<\/p>\n

    You know one way to record partial sums.
    \n\"Envision
    \n\"Envision<\/p>\n

    A.
    \nJason’s family drove from Ocala, Florida to Miami. They drove 139 miles in the morning and 187 miles in the afternoon. How far did Jason’s family drive? Find 139 + 187. ?
    \n\"Envision
    \nEstimate: 139 + 187 is about 100 + 200, or 300 miles.
    \nJason’s family drove 326 miles. 300 is close to 326, so the sum is reasonable.<\/p>\n

    B.<\/strong>
    \nHere is another way. Write the partial sums.
    \n\"Envision
    \nRegroup the ones. 16 ones = 1 ten + 6 ones
    \n\"Envision
    \nRegroup the tens. 12 tens = 1 hundred + 2 tens
    \n\"Envision<\/p>\n

    When you regroup, you name a whole number in a different way.
    \n\"Envision<\/p>\n

    139 + 187 = 326
    \nJason’s family drove 326 miles.<\/p>\n

    Convince Me!<\/strong>
    \nModel with Math<\/strong> Show how to use place-value blocks to find 128 +235 using regrouping.<\/p>\n

    Another Example!<\/strong><\/p>\n

    Find 154 + 163.
    \n\"Envision<\/p>\n

    You can find partial sums. Then you can regroup place values to find the final sum.
    \n\"Envision
    \nRegroup the tens.
    \n1 hundred + 1 ten = 11 tens
    \n154 + 163 = 317<\/p>\n

    Guided Practice<\/strong><\/p>\n

    Do You Understand?<\/strong><\/p>\n

    Question 1.
    \nWhen you add 3-digit numbers, how do you know if you need to regroup?
    \nAnswer: When you add 3-digit numbers if the sum of the place value is greater than 9 then we can know we have to regroup the addend.<\/p>\n

    Question 2.
    \nTo add 546 + 327, would you need to regroup? Explain.
    \nAnswer:
    \n546 + 327
    \n7 + 6 = 13, yes we need to regroup
    \n546 + 327 = 873<\/p>\n

    Do You Know How?<\/strong><\/p>\n

    In 3 and 4, estimate by rounding. Then find each sum. Use place-value blocks or drawings to help.<\/p>\n

    Question 3.
    \n\"Envision
    \nAnswer:
    \n\"Envision-Math-Common-Core-Grade-3-Answer-Key-Topic-9-Fluently-Add-and-Subtract-within-1000-17.1\"<\/p>\n

    Question 4.
    \n\"Envision
    \nAnswer:
    \n\"Envision-Math-Common-Core-Grade-3-Answer-Key-Topic-9-Fluently-Add-and-Subtract-within-1000-17.2\"<\/p>\n

    Independent Practice<\/strong><\/p>\n

    In 5-12, estimate and then find each sum.<\/p>\n

    Question 5.
    \n\"Envision
    \nAnswer:
    \nThe estimated number of 136 is 100.
    \nThe estimated number of 252 is 300.
    \nThe sum of 100 and 300 is 400.
    \n\"Envision-Math-Common-Core-Grade-3-Answer-Key-Topic-9-Fluently-Add-and-Subtract-within-1000-17.3\"<\/p>\n

    Question 6.
    \n\"Envision
    \nAnswer:
    \nThe estimated number of 678 is 700.
    \nThe estimated number of 129 is 100.
    \nThe sum of 700 and 100 is 800.
    \n\"Envision-Math-Common-Core-Grade-3-Answer-Key-Topic-9-Fluently-Add-and-Subtract-within-1000-17.4\"<\/p>\n

    Question 7.
    \n\"Envision
    \nAnswer:
    \nThe estimated number of 564 is 600.
    \nThe estimated number of 283 is 300.
    \nThe sum of 600 and 300 is 900.
    \n\"Envision-Math-Common-Core-Grade-3-Answer-Key-Topic-9-Fluently-Add-and-Subtract-within-1000-17.5\"<\/p>\n

    Question 8.
    \n\"Envision
    \nAnswer:
    \nThe estimated number of 118 is 100.
    \nThe estimated number of 335 is 300.
    \nThe sum of 100 and 300 is 400.
    \n\"Envision-Math-Common-Core-Grade-3-Answer-Key-Topic-9-Fluently-Add-and-Subtract-within-1000-17.6\"<\/p>\n

    Question 9.
    \n172 + 534
    \nAnswer:
    \nThe estimated number of 172 is 200.
    \nThe estimated number of 534 is 500.
    \nThe sum of 200 and 500 is 700.<\/p>\n

    Question 10.
    \n324 + 508
    \nAnswer:
    \nThe estimated number of 324 is 300.
    \nThe estimated number of 508 is 500.
    \nThe sum of 300 and 500 is 800.<\/p>\n

    Question 11.
    \n582 + 230
    \nAnswer:
    \nThe estimated number of 582 is 600.
    \nThe estimated number of 230 is 200.
    \nThe sum of 600 and 200 is 800.<\/p>\n

    Question 12.
    \n207 + 238
    \nAnswer:
    \nThe estimated number of 207 is 200.
    \nThe estimated number of 238 is 200.
    \nThe sum of 200 and 200 is 400.<\/p>\n

    Problem Solving<\/strong><\/p>\n

    In 13 and 14, use the table at the right.<\/p>\n

    Question 13.
    \nHow many soup can labels did Grades 1 and 2 collect? Estimate by rounding to the nearest hundred. Then solve. Write an equation that represents the problem.
    \n\"Envision
    \nAnswer:
    \nEstimate: 400 + 300 = 700
    \n385 + 294 = 679, grade 1 and 2 collected 679 labels.<\/p>\n

    Question 14.
    \nMake Sense and Persevere<\/strong> Is your answer to Exercise 13 reasonable? Explain.
    \nAnswer: Yes, 679 is close to my estimate of 700, so 679 is a reasonable answer.<\/p>\n

    Question 15.
    \nNumber Sense<\/strong> The roller coaster Kingda Ka is 192 feet taller than the first Ferris wheel. Use the symbols < and > to compare the heights of the two rides in two different ways.
    \n\"Envision<\/p>\n

    Answer: 264 feet < 456 feet; 456 feet > 264 feet<\/p>\n

    Question 16.
    \nHigher Order Thinking<\/strong> Pete can run 178 yards in one minute. Sharon can run 119 more yards than Pete in one minute. How many yards can they both run in one minute?
    \nAnswer:
    \nGiven,
    \nPete can run 178 yards in one minute.
    \nSharon can run 119 more yards than Pete in one minute.
    \n178 + 119 = 297 yards
    \n178 + 297 = 475 yards<\/p>\n

    Question 17.
    \nAbi practiced her flute for 215 minutes last week and 178 minutes this week. How many minutes has Abi practiced?
    \nAnswer:
    \nGiven,
    \nAbi practiced her flute for 215 minutes last week and 178 minutes this week.
    \n215 + 178 = 393
    \nThus Abi practiced 393 minutes.<\/p>\n

    Assessment Practice<\/strong><\/p>\n

    Question 18.
    \nWhat is 126 + 229?
    \nA. 355
    \nB. 345
    \nC. 255
    \nD. 245
    \nAnswer: 355
    \nThe sum of 126 and 229 is 355.
    \nThus the correct answer is option A.<\/p>\n

    Question 19.
    \nWhat is the value of the unknown in 248 + \"Envision = 521?
    \nA. 248
    \nB. 263
    \nC. 273
    \nD. 283
    \nAnswer: 273
    \nLet the missing number be x.
    \n248 + x = 521
    \nx = 521 – 248
    \nx = 273
    \nThus the correct answer is option C.<\/p>\n

    Lesson 9.3 Add 3 or More Numbers<\/h3>\n

    Activity<\/strong><\/p>\n

    Solve & Share<\/strong><\/p>\n

    A pet store has 162 goldfish, 124 angelfish, and 6 bowls with 9 pufferfish in each. How many fish are there in all?<\/p>\n

    You can generalize. Use what you know about adding two numbers to add three numbers.
    \n\"Envision<\/p>\n

    Look Back!<\/strong> How can you decide if your answer is reasonable?<\/p>\n

    Visual Learning Bridge<\/strong><\/p>\n

    Essential Question
    \n<\/strong>How Can You Add More Than Two Numbers?<\/p>\n

    A.<\/strong>
    \nDifferent kinds of birds are for sale at a pet store. How many birds are for sale?
    \nFind 137 + 155 + 18.
    \nRound to the nearest ten to estimate: 140 + 160 + 20 = 320.
    \n\"Envision<\/p>\n

    B.<\/strong>
    \nOne Way<\/strong>
    \nUse partial sums.
    \n\"Envision
    \nIn all, 310 birds are for sale.<\/p>\n

    C.<\/strong>
    \nAnother Way<\/strong>
    \nUse column addition.
    \n\"Envision
    \nThe answer is reasonable because 310 is close to the estimate of 320.
    \n\"Envision
    \nIn all, 310 birds are for sale.<\/p>\n

    Convince Me!<\/strong>
    \nModel with Math<\/strong> For the partial sums above, Billy said, \u201c20 plus 90 is 110. 110 plus 200 equals 310.” Is Billy correct? Use models, properties, or equations to represent and explain your thinking.<\/p>\n

    Guided Practice<\/strong><\/p>\n

    Do You Understand?<\/strong><\/p>\n

    In 1 and 2, look at the example on the previous page.<\/p>\n

    Question 1.
    \nIf you add the numbers in this order, do you get the same sum? Explain why or why not.
    \n\"Envision
    \nAnswer:
    \n\"Envision-Math-Common-Core-3rd-Grade-Answers-Topic-9-Fluently-Add-and-Subtract-within-1000-31.1\"<\/p>\n

    Question 2.
    \nWhy is the 20 crossed out in the column addition problem?
    \nAnswer: 5 + 7 + 8 = 20<\/p>\n

    Do You Know How?<\/strong><\/p>\n

    In 3 and 4, estimate and then find each sum.<\/p>\n

    Question 3.
    \n\"Envision
    \nAnswer:
    \nThe number 123 round to the nearest ten is 120.
    \nThe number 168 round to the nearest ten is 170.
    \nThe number 36 round to the nearest ten is 40.
    \n\"Envision-Math-Common-Core-3rd-Grade-Answers-Topic-9-Fluently-Add-and-Subtract-within-1000-31.2\"
    \nThus the estimated sum is 330.<\/p>\n

    Question 4.
    \n\"Envision
    \nAnswer:
    \nThe number 247 round to the nearest ten is 250.
    \nThe number 362 round to the nearest ten is 360.
    \nThe number 149 round to the nearest ten is 150.
    \n\"Envision-Math-Common-Core-3rd-Grade-Answers-Topic-9-Fluently-Add-and-Subtract-within-1000-31.3\"
    \nThus the estimated sum is 760.<\/p>\n

    You can use partial sums or column addition to add.
    \n\"Envision<\/p>\n

    Independent Practice<\/strong><\/p>\n

    Leveled Practice<\/strong> In 5-15, estimate and then find each sum.<\/p>\n

    Question 5.
    \n\"Envision
    \nAnswer:
    \nThe number 64 round to the nearest ten is 60.
    \nThe number 42 round to the nearest ten is 40.
    \nThe number 88 round to the nearest ten is 90.
    \n60 + 40 + 90 = 190
    \n\"Envision-Math-Common-Core-3rd-Grade-Answers-Topic-9-Fluently-Add-and-Subtract-within-1000-31.6\"
    \nThus the estimated sum is 190.<\/p>\n

    Question 6.
    \n\"Envision
    \nAnswer:
    \nThe number 354 round to the nearest ten is 350.
    \nThe number 85 round to the nearest ten is 90.
    \nThe number 72 round to the nearest ten is 70.
    \n350 + 90 + 70 = 510
    \n\"Envision-Math-Common-Core-3rd-Grade-Answers-Topic-9-Fluently-Add-and-Subtract-within-1000-31.7\"
    \nThus the estimated sum is 510.<\/p>\n

    Question 7.
    \n\"Envision
    \nAnswer:
    \nThe number 307 round to the nearest ten is 310.
    \nThe number 37 round to the nearest ten is 40.
    \nThe number 234 round to the nearest ten is 230.
    \n310 + 40 + 230 = 580
    \n\"Envision-Math-Common-Core-3rd-Grade-Answers-Topic-9-Fluently-Add-and-Subtract-within-1000-31.8\"
    \nThus the estimated sum is 580.<\/p>\n

    Question 8.
    \n\"Envision
    \nAnswer:
    \nThe number 714 round to the nearest ten is 710.
    \nThe number 163 round to the nearest ten is 160.
    \nThe number 99 round to the nearest ten is 100.
    \n710 + 160 + 100 = 970
    \n\"Envision-Math-Common-Core-3rd-Grade-Answers-Topic-9-Fluently-Add-and-Subtract-within-1000-31.9\"
    \nThus the estimated sum of the above numbers is 970<\/p>\n

    Question 9.
    \n\"Envision
    \nAnswer:
    \nThe number 602 round to the nearest ten is 600.
    \nThe number 125 round to the nearest ten is 130.
    \nThe number 231 round to the nearest ten is 230.
    \n600 + 130 + 230 = 960
    \nThus the estimated sum of the above numbers is 960.
    \n\"Envision-Math-Common-Core-3rd-Grade-Answers-Topic-9-Fluently-Add-and-Subtract-within-1000-40.1\"<\/p>\n

    Question 10.
    \n\"Envision
    \nAnswer:
    \nThe number 64 round to the nearest ten is 60.
    \nThe number 42 round to the nearest ten is 40.
    \nThe number 88 round to the nearest ten is 90.<\/p>\n

    Question 11.
    \n\"Envision
    \nAnswer:
    \nThe number 64 round to the nearest ten is 60.
    \nThe number 42 round to the nearest ten is 40.
    \nThe number 88 round to the nearest ten is 90.<\/p>\n

    Question 12.
    \n\"Envision
    \nAnswer:
    \nThe number 125 round to the nearest ten is 130.
    \nThe number 35 round to the nearest ten is 40.
    \nThe number 124 round to the nearest ten is 120.
    \nThe number 239 round to the nearest ten is 240.
    \n130 + 40 + 120 + 240 = 530
    \n\"Envision-Math-Common-Core-3rd-Grade-Answers-Topic-9-Fluently-Add-and-Subtract-within-1000-40.4\"
    \nSo, the sum of 125, 35, 124, 239 is 523.<\/p>\n

    Question 13.
    \n32 + 9 + 56 +8
    \nAnswer:
    \nWhen we add 32 + 9 + 56 +8 we get 105.
    \nThe number 105 round to the nearest hundred is 100.
    \nThus the estimated sum is 100.<\/p>\n

    Question 14.
    \n481 + 78 + 42
    \nAnswer:
    \nWhen we add 481 + 78 + 42 we get 601.
    \nThe number 601 round to the nearest hundred is 600.
    \nThus the estimated sum is 600.<\/p>\n

    Question 15.
    \n398 + 219 + 23 + 251
    \nAnswer:
    \nWhen we add 398 + 219 + 23 + 251 we get 891.
    \nThe number 891 round to the nearest hundred is 900.
    \nThus the estimated sum is 900.<\/p>\n

    Problem Solving<\/strong><\/p>\n

    Question 16.
    \nUse the picture at the right to find the height of President Washington’s head carved in Mt. Rushmore. Write an equation to solve the problem.
    \n\"Envision
    \nAnswer:
    \nAdd all the numbers to find the height of President Washington’s head carved in Mt. Rushmore.
    \n228 + 252 + 240 = 720 inches<\/p>\n

    Question 17.
    \nAlgebra<\/strong> Jada spends $74 on a hat, shoes, and shorts. If the hat costs $22 and the shoes cost $33, how much were the shorts? Write and solve an equation. Use an unknown to represent the cost of the shorts.
    \nAnswer:
    \nGiven,
    \nJada spends $74 on a hat, shoes, and shorts.
    \nThe hat costs $22 and the shoes cost $33
    \n22 + 33 + x = 74
    \n55 + x = 74
    \nx = 74 – 55
    \nx = 19
    \nThus the cost of shorts is $19.<\/p>\n

    Question 18.
    \nHigher Order Thinking<\/strong> Meg says 95 + 76 + 86 is greater than 300, but less than 400. Is Meg correct? Why or why not?
    \nAnswer:
    \nNo Meg is not correct.
    \n95 + 76 + 86 = 257
    \nSo, 257 is smaller than 300.
    \nBy this we can say that Meg is wrong.<\/p>\n

    Question 19.
    \nReasoning<\/strong> Karin had cereal, a glass of milk, and a banana for breakfast. How many calories were in her meal? Round to the nearest ten to estimate and then solve. Write an equation that includes your solution.
    \n\"Envision
    \nAnswer:
    \nGiven,
    \nKarin had cereal, a glass of milk, and a banana for breakfast.
    \n105 round to the nearest ten is 100.
    \n110 round to the nearest ten is 110.
    \n150 round to the nearest ten is 150.
    \nNow add the numbers 100 + 110 + 150 = 360
    \nThus the equation is 100 + 110 + 150 = 360<\/p>\n

    Assessment Practice<\/strong><\/p>\n

    Question 20.
    \nUse place value, partial sums, or properties of operations to find each sum.
    \n\"Envision
    \nAnswer:
    \n\"Envision-Math-Common-Core-3rd-Grade-Answers-Topic-9-Fluently-Add-and-Subtract-within-1000-52.5\"<\/p>\n

    Question 21.
    \nUse place value, column addition, or of operations to find each sum.
    \n\"Envision
    \nAnswer:
    \n\"Envision-Math-Common-Core-3rd-Grade-Answers-Topic-9-Fluently-Add-and-Subtract-within-1000-52.6\"<\/p>\n

    Lesson 9.4 Use Partial Differences to Subtract<\/h3>\n

    Activity<\/strong><\/p>\n

    Solve & Share<\/strong><\/p>\n

    Find the difference of 534 \u2013 108. Think about how place value can help you subtract.<\/p>\n

    You can use structure. How could you use place value to help solve the problem?
    \n\"Envision<\/p>\n

    Look Back!<\/strong> Jim had 388 marbles. He gave 8 marbles to each of 7 friends. How many marbles does Jim have left? How can place value help you to subtract 3-digit numbers?<\/p>\n

    Visual Learning Bridge<\/strong><\/p>\n

    Essential Question<\/strong>
    \nHow Can You Use Partial Differences to Subtract?<\/p>\n

    A.<\/strong>
    \nAt the end of the fourth round of a game of Digit Derby, Marco’s score was 462 points. During the fifth round of the game, Marco loses points. What is Marco’s score at the end of the fifth round? Find 462 \u2013 181.
    \n\"Envision
    \nEstimate first.
    \n462 \u2013 181 = ?
    \n500 \u2013 200 = 300
    \nPlace value can help you break a subtraction problem into smaller problems.
    \n\"Envision<\/p>\n

    B.<\/strong>
    \nWhat You Think<\/strong>
    \nUse place value to subtract.
    \nCount back by hundreds, tens, and ones.
    \n181 = 100 + 80 + 1
    \nStart at 462. Count back 100 to 362.
    \nCount back 80 to 282
    \nBreak apart 80 into 60 and 20.
    \nCount back 1 to 281.
    \n\"Envision<\/p>\n

    C.<\/strong>
    \nWhat You Write<\/strong>
    \n\"Envision
    \nAt the end of the fifth round, Marco’s score is 281 points.
    \nThe score is close to the estimate.
    \nThe difference is reasonable.<\/p>\n

    Convince Me!<\/strong>
    \nBe Precise<\/strong> Why was 80 broken into 60 and 20 in the computation above?<\/p>\n

    Guided Practice<\/strong><\/p>\n

    Do You Understand?<\/strong><\/p>\n

    Question 1.
    \nWhy do you need to record the numbers you subtract at each step?
    \nAnswer:
    \nTo keep track of where you are in an equation, and to allow you to retrace your steps if you happen to do something wrong.<\/p>\n

    Question 2.
    \nAna is trying to find 634 \u2013 210. She decides to start by subtracting 10 from 634. Do you agree with Ana? Explain.
    \nAnswer:<\/p>\n

    Do You Know How?<\/strong><\/p>\n

    In 3 and 4, estimate and then use partial differences to subtract. Use open number lines to help.<\/p>\n

    Question 3.
    \nFind 374 \u2013 236.
    \n\"Envision
    \nAnswer:
    \n\"Envision-Math-Common-Core-3rd-Grade-Answers-Topic-9-Fluently-Add-and-Subtract-within-1000-55.1\"<\/p>\n

    Question 4.
    \nFind 369 \u2013 175.
    \n\"Envision
    \nAnswer:
    \n\"Envision-Math-Common-Core-3rd-Grade-Answers-Topic-9-Fluently-Add-and-Subtract-within-1000-55.2\"<\/p>\n

    Independent Practice<\/strong><\/p>\n

    In 5-10, estimate and then use partial differences to subtract. Use open number lines to help.<\/p>\n

    Question 5.
    \n738 \u2013 523
    \n\"Envision
    \nAnswer: 215<\/p>\n

    Question 6.
    \n755 \u2013 315
    \n\"Envision
    \nAnswer: 440<\/p>\n

    Question 7.
    \n336 – 217
    \n\"Envision
    \nAnswer: 119<\/p>\n

    Question 8.
    \n455 \u2013\u00a0 \u00a0182
    \n\"Envision
    \nAnswer: 273<\/p>\n

    Question 9.
    \n865 \u2013 506
    \n\"Envision
    \nAnswer: 359<\/p>\n

    Question 10.
    \n794 \u2013 355
    \n\"Envision
    \nAnswer: 439<\/p>\n

    Problem Solving<\/strong><\/p>\n

    Question 11.
    \nDon’s book has 316 pages. He read 50 pages last week. He read another 71 pages this week. How many more pages does Don have left to read?
    \nAnswer:
    \ntotal number of pages in Don’s book = 316
    \nDon’s read pages in last week = 50
    \nDon’s read pages in this week = 71
    \nDon have to left to read pages = 316 – 50 + 71 = 195<\/p>\n

    Question 12.
    \nVocabulary<\/strong> Explain why it is necessary to regroup when adding 172 + 264.
    \nAnswer:
    \n264
    \n172<\/span>
    \n436
    \nRegrouping is used when the addition of two numbers is greater than 9.
    \nHere 7 + 6 = 13
    \n13 > 10
    \nSo, regrouping is necessary here.
    \nTherefore regrouping is necessary when adding 172 + 264<\/p>\n

    Question 13.
    \nUse Structure<\/strong> Beth had a necklace with 128 beads. The string broke, and she lost 49 beads. How many beads does Beth have left? Explain how you can break the problem into smaller problems to solve.
    \nAnswer:
    \nBeth had a necklace with beads = 128
    \nThe string broke and she lost beads =49
    \nBeads left with Beth = 128 – 49 = 79<\/p>\n

    Question 14.
    \nWrite the time shown on the clock in two different ways.
    \n\"Envision
    \nAnswer:
    \n9: 15
    \n21 : 15<\/p>\n

    Question 15.
    \nHigher Order Thinking<\/strong> Which weighs more, two Basset Hounds or one Great Dane? Show the difference in pounds between two Basset Hounds and a Great Dane. Draw bar diagrams to represent and help solve the problem.
    \n\"Envision
    \nAnswer:
    \nThe weight of two basset hounds = 66 + 66 = 132pounds
    \nThe weight of one great dane = 145\u00a0 pounds
    \nThe weight of one grate dane is greater than two basset hounds.<\/p>\n

    Assessment Practice<\/strong><\/p>\n

    Question 16.
    \nWhich have a difference of 181? Use place value and partial differences to solve. Select all that apply.
    \n\"Envision 428 \u2013 247 = ?
    \n\"Envision 562 \u2013 381 = ?
    \n\"Envision 498 \u2013 307 = ?
    \n\"Envision 875 \u2013 696 = ?
    \n\"Envision 946 \u2013 765 = ?
    \nAnswer:
    \n\"Envision-Math-Common-Core-Grade-3-Answers-Topic-9-Fluently-Add-and-Subtract-within-1000-62\"428 \u2013 247 = 181
    \n\"Envision-Math-Common-Core-Grade-3-Answers-Topic-9-Fluently-Add-and-Subtract-within-1000-62\"562 \u2013 381 = 181
    \n\"Envision-Math-Common-Core-Grade-3-Answers-Topic-9-Fluently-Add-and-Subtract-within-1000-61\"498 \u2013 307 = 191
    \n\"Envision-Math-Common-Core-Grade-3-Answers-Topic-9-Fluently-Add-and-Subtract-within-1000-61\"875 \u2013 696 = 179
    \n\"Envision-Math-Common-Core-Grade-3-Answers-Topic-9-Fluently-Add-and-Subtract-within-1000-62\"946 \u2013 765 = 181<\/p>\n

    Question 17.
    \nWhich have a difference of 237? Select all that apply.
    \n\"Envision 877 \u2013 640 = ?
    \n\"Envision 412 \u2013 176 = ?
    \n\"Envision 652 \u2013 415 = ?
    \n\"Envision 700 \u2013 459 = ?
    \n\"Envision 802 \u2013 565 = ?
    \nAnswer:
    \n\"Envision-Math-Common-Core-Grade-3-Answers-Topic-9-Fluently-Add-and-Subtract-within-1000-62\" 877 \u2013 640 = 237
    \n\"Envision-Math-Common-Core-Grade-3-Answers-Topic-9-Fluently-Add-and-Subtract-within-1000-61\"412 \u2013 176 = 236
    \n\"Envision-Math-Common-Core-Grade-3-Answers-Topic-9-Fluently-Add-and-Subtract-within-1000-62\" 652 \u2013 415 = 237
    \n\"Envision-Math-Common-Core-Grade-3-Answers-Topic-9-Fluently-Add-and-Subtract-within-1000-61\"700 \u2013 459 = 241
    \n\"Envision-Math-Common-Core-Grade-3-Answers-Topic-9-Fluently-Add-and-Subtract-within-1000-62\" 802 \u2013 565 = 237<\/p>\n

    Lesson 9.5 Use Regrouping to Subtract<\/h3>\n

    Activity<\/strong><\/p>\n

    Solve & Share<\/strong><\/p>\n

    Last year, there were 347 houses for sale in Mill County and 289 houses for sale in Hunter County. Of the houses for sale in both counties, 162 were sold. How many houses were not sold? Solve this problem two different ways.<\/p>\n

    You can generalize when you subtract 3-digit numbers. Think about all the strategies you can use.
    \n\"Envision<\/p>\n

    Look Back!<\/strong> How are your solution strategies alike and how are they different?<\/p>\n

    Visual Learning Bridge<\/strong><\/p>\n

    Essential Question<\/strong><\/p>\n

    How Can You Use Regrouping to Solve Subtraction Problems?<\/p>\n

    Glossary<\/strong><\/p>\n

    A.<\/strong>
    \nMike and Linda play a game. Linda has 528 points. Mike has 349 points. How many more points does Linda have than Mike? Find 528 – 349.
    \nEstimate:
    \n528 – 349 = ?
    \n530 \u2013 350 = 180
    \n\"Envision<\/p>\n

    B.<\/strong>
    \nDraw place-value blocks to show 528.
    \n\"Envision<\/p>\n

    C.<\/strong> Subtract 9 ones.
    \n\"Envision
    \nRegroup 1 ten as 10 ones.
    \n\"Envision
    \nYou can use place value to regroup when subtracting.<\/p>\n

    Subtract 4 tens. 528
    \n\"Envision
    \nRegroup 1 hundred as 10 tens.
    \n\"Envision<\/p>\n

    Subtract 3 hundreds.
    \n\"Envision
    \n179 is close to the estimate.<\/p>\n

    Convince Me!<\/strong>
    \nUse Appropriate Tools How could you use a tool to find 326 \u2013 143?<\/p>\n

    Guided Practice<\/strong><\/p>\n

    Do You Understand?<\/strong><\/p>\n

    Question 1.
    \nIn the example on the previous page, explain how to decide if regrouping is necessary
    \nAnswer:<\/p>\n

    Question 2.
    \nWhat strategies could you use to find 507 \u2013 348?
    \nAnswer:
    \nusing the mental math
    \n500 + 7 – 300 + 40 + 8
    \n500 + 7 – 300 + 48
    \n200 +7 -48\u00a0 = 159
    \nDo You Know How?<\/strong><\/p>\n

    In 3 and 4, estimate each difference and then use partial differences to subtract.<\/p>\n

    Question 3.
    \n\"Envision
    \nAnswer:
    \nestimated difference
    \n370
    \n–\u00a0 180
    \n190\u00a0\u00a0<\/span><\/p>\n

    Question 4.
    \n\"Envision
    \nAnswer:
    \nestimated difference
    \n860
    \n– 220\u00a0<\/span>
    \n\u00a0 \u00a0640\u00a0<\/span><\/p>\n

    Independent Practice<\/strong><\/p>\n

    In 5-12, estimate each difference and then use partial differences to subtract.<\/p>\n

    Question 5.
    \n\"Envision
    \nAnswer:
    \nestimated difference
    \n430
    \n-140<\/span>
    \n\u00a0 \u00a0<\/span>290\u00a0<\/span><\/p>\n

    Question 6.
    \n\"Envision
    \nAnswer:
    \nestimated difference
    \n280
    \n–\u00a0 100\u00a0<\/span>
    \n\u00a0 \u00a0180\u00a0<\/span><\/p>\n

    Question 7.
    \n\"Envision
    \nAnswer:
    \nestimated difference
    \n520
    \n–\u00a0 400\u00a0<\/span>
    \n\u00a0 \u00a0120\u00a0\u00a0<\/span><\/p>\n

    Question 8.
    \n\"Envision
    \nAnswer:
    \nestimated difference
    \n530
    \n–\u00a0 240\u00a0<\/span>
    \n\u00a0 \u00a0290\u00a0 \u00a0<\/span><\/p>\n

    Question 9.
    \n574 \u2013 86
    \nAnswer:
    \nestimated difference
    \n570 – 90 = 480<\/p>\n

    Question 10.
    \n629 \u2013 453
    \nAnswer:
    \nestimated difference
    \n630 – 450 = 180<\/p>\n

    Question 11.
    \n979 \u2013 569
    \nAnswer:
    \nestimated difference
    \n980 – 570 = 410<\/p>\n

    Question 12.
    \n764 \u2013 237
    \nAnswer:
    \nestimated difference
    \n760 – 240 = 520<\/p>\n

    Problem Solving<\/strong><\/p>\n

    Question 13.
    \nAt the end of their game, Lora had 426 points and Theo had 158 points. How many more points did Lora have than Theo?
    \n\"Envision
    \nAnswer: 268
    \nGiven
    \nLora had 426 points and Theo had 158 points
    \nto find How many more points did Lora have than Theo
    \nhence 426 subtract with 158 we get 268<\/p>\n

    Question 14.
    \nModel with Math<\/strong> Zac and Malcolm each wrote short stories. Zac’s story is 272 lines long. Malcolm’s story is 145 lines longer than Zac’s. How long is Malcolm’s story? Explain how you can model with math to solve this problem.
    \nAnswer:
    \nGiven,
    \nZac and Malcolm each wrote short stories. Zac’s story is 272 lines long.
    \nMalcolm’s story is 145 lines longer than Zac’s.
    \n272 + 145 = 417
    \nTherefore, Malcolm wrote 417 lines long.<\/p>\n

    Question 15.
    \nThe world’s largest basket is 186 feet tall from the base to the top of the handles. What is the height of the handles?
    \n\"Envision
    \nAnswer: 83 feet
    \ngiven
    \nThe world’s largest basket is 186 feet tall from the base to the top of the handles.
    \nbase to basket 103 feets
    \nto find the height of the handles
    \nhence 186 feet subtract with 103 feet we get 83 feet<\/p>\n

    Question 16.
    \nHigher Order Thinking<\/strong> How many more swimmers signed up for the 1st session at Oak Pool than the 1st and 2nd sessions at Park Pool combined? Write an equation that represents the problem and includes the solution.
    \n\"Envision
    \nAnswer:
    \ngiven data
    \nwe have to find How many more swimmers signed up for the 1st session at Oak Pool than the 1st and 2nd sessions at Park Pool combined
    \nhence oak pool 1st session 763 subtract with 2nd session 586 we get 177
    \noak pool 1st session 314 subtract with 2nd session 179 we get\u00a0 135
    \noak pool 1st session 256 subtract with 2nd session 163 we get\u00a0 93<\/p>\n

    Assessment Practice<\/strong><\/p>\n

    Question 17.
    \nWhich shows the estimate of 627 \u2013 441 by rounding to the nearest ten, and then the correct difference?
    \nA. 200; 186
    \nB. 200; 176
    \nC. 190; 186
    \nD. 190; 176
    \nAnswer: C
    \nestimate of 627 \u2013 441 we get 186
    \nestimated 630 – 440 we get 190<\/p>\n

    Question 18.
    \nWhich shows the estimate of 901 \u2013 512 by rounding to the nearest ten, and then the correct difference?
    \nA. 390; 389
    \nB. 390; 379
    \nC. 400; 389
    \nD. 400; 379
    \nAnswer: A
    \nestimate of 901 \u2013 512 we get 389
    \nestimated 900 – 510 we get 390<\/p>\n

    Lesson 9.6 Use Strategies to Add and Subtract<\/h3>\n

    Activity<\/strong><\/p>\n

    Solve & Share<\/strong><\/p>\n

    Rick is allowed to receive 1,000 text messages each month. How many more text messages can Rick receive this month? Solve any way you choose. Explain how you found the answer.
    \n\"Envision
    \nUse reasoning. First think about the operations you should use.
    \n\"Envision
    \nLook Back!<\/strong> Is your answer reasonable? How can you check?<\/p>\n

    Visual Learning Bridge<\/strong><\/p>\n

    Essential Question<\/strong> How Can You Use Strategies to Add and Subtract?<\/p>\n

    A.<\/strong>
    \nThere are 136 fewer cell phone towers in Jurloe County than in Fraser County. How many cell phone towers are there in Jurloe County? Choose a strategy, and then solve.
    \n\"Envision
    \n402 is about 400.
    \n136 is about 100.
    \nThe difference is about 300.<\/p>\n

    You can use addition or subtraction to solve.
    \n402 = ? + 136
    \n402 \u2013 136 = ?
    \nAddition and subtraction are inverse operations.
    \n\"Envision
    \n\"Envision<\/p>\n

    B.<\/strong>
    \nOne Way<\/strong> Use the adding on strategy.
    \nFind 402 = ? + 136.
    \n\"Envision
    \nThere are 266 cell phone towers in Jurloe County.<\/p>\n

    C.<\/strong>
    \nAnother Way<\/strong>
    \nThe answer is reasonable because it is close to the estimate of 300.
    \nUse partial differences to subtract.
    \nThe answer is reasonable because it differences to is close to the estimate of 300.
    \nFind 402 \u2013 136 = ?
    \n\"Envision
    \n\"Envision
    \nThere are 266 cell phone towers in Jurloe County.<\/p>\n

    Convince Me!<\/strong> Use Appropriate Tools Show how to use a tool (such as a number line or place-value blocks) to solve the problem above.<\/p>\n

    Another Example!<\/strong>
    \nThe Yellowstone River is 692 miles long. It is 51 miles shorter than the Kansas River. How long is the Kansas River? Choose a strategy, and then solve. Find 692 + 51 = ?
    \n\"Envision
    \n\"Envision
    \nThe Kansas River is 743 miles long.<\/p>\n

    Guided Practice<\/strong><\/p>\n

    Do You Understand?<\/strong><\/p>\n

    Question 1.
    \nTo subtract 507 \u2013 348, how can you regroup the tens if there are 0 tens?
    \nAnswer:
    \nSubtract the ones.
    \n7 ones > 8 ones
    \nSince there are no tens in 507, regroup the hundreds.
    \n5 hundreds and 0 tens = 4 hundreds 10 tens
    \nRegroup the tens
    \n10 tens and 7 ones = 9 tens and 17 ones
    \nSubtract the ones, tens and then the hundreds.
    \nSo, 507 – 348 = 159<\/p>\n

    Question 2.
    \nHow is using partial sums to add like using place-value blocks and regrouping?
    \nAnswer: Thinking of the place value of digits in the numbers, Finding partial sums by adding parts of numbers according to their place value, and \u2022 Adding partial sums together to get a total.<\/p>\n

    Do You Know How?<\/strong><\/p>\n

    In 3-6, estimate and then find each sum or difference.<\/p>\n

    Question 3.
    \n\"Envision
    \nAnswer:
    \n816 subtract with 335 we get 481
    \nestimated 820 subtract with 340 we get 480<\/p>\n

    Question 4.
    \n\"Envision
    \nAnswer:
    \n163 add with 50 we get 213
    \nestimated 160 add with 50 we get 210<\/p>\n

    Question 5.
    \n\"Envision
    \nAnswer:
    \n900 subtract with 375 we get 535
    \nestimated 900 subtract with 370 we get 530<\/p>\n

    Question 6.
    \n\"Envision
    \nAnswer:
    \n508 subtract with 247we get 261
    \nestimated 510 subtract with 250 we get 260<\/p>\n

    Independent Practice<\/strong><\/p>\n

    In 7-14, find each sum or difference. Then use estimation to check your answer.<\/p>\n

    Question 7.
    \n\"Envision
    \nAnswer:
    \n549 subtract with 167 we get 382
    \nestimated 550 subtract with 170 we get 380<\/p>\n

    Question 8.
    \n\"Envision
    \nAnswer:
    \n411 subtract with 238 we get 173
    \nestimated 410 subtract with 240 we get 170<\/p>\n

    Question 9.
    \n\"Envision
    \nAnswer:
    \n560 add with 144 we get 704
    \nestimated 560 add with 140 we get 700<\/p>\n

    Question 10.
    \n\"Envision
    \nAnswer:
    \n783 add with 68 we get 851
    \nestimated 780 add with 70 we get 850<\/p>\n

    Question 11.
    \n400 \u2013 219
    \nAnswer:
    \n400 subtract with 219 we get 619
    \nestimated 400 subtract with 220 we get 620<\/p>\n

    Question 12.
    \n904 \u2013 703
    \nAnswer:
    \n904 subtract with 703 we get 201
    \nestimated 900 subtract with 700 we get 200<\/p>\n

    Question 13.
    \n700 + 64
    \nAnswer:
    \n700 add with 64 we get 764
    \nestimated 700 add with 60 we get 760<\/p>\n

    Question 14.
    \n807 + 38
    \nAnswer:
    \n807 add with 38 we get 845
    \nestimated 800 add with 40 we get 840<\/p>\n

    Problem Solving<\/strong><\/p>\n

    Question 15.
    \nHow much more money does the Elm School Art Club need to raise? Complete the bar diagram and solve the problem.
    \nElm School
    \n\"Envision
    \n\"Envision
    \nAnswer:
    \nBy seeing the above figure we can find the amount of money to reach the goal.
    \n\"Envision-Math-Common-Core-3rd-Grade-Answer-Key-Topic-9-Fluently-Add-and-Subtract-within-1000-78.1\"
    \n$305 – $178 = $127
    \nTherefore, the amount of money to reach goal is $127.<\/p>\n

    Question 16.
    \nThere were some ears of corn for sale at the farmers’ market. Three hundred eighty-eight ears of corn were sold. At the end, there were 212 ears left. How many ears of corn were for sale at the start?
    \nAnswer:
    \nGiven,
    \nThere were some ears of corn for sale at the farmers’ market.
    \nThree hundred eighty-eight ears of corn were sold.
    \nAt the end, there were 212 ears left.
    \n388 + 212 = 600
    \nThus there were 600 ears of corn for sale at the start.<\/p>\n

    Question 17.
    \nDina was adding books to the library shelves. She put 117 nonfiction books on the shelves. Then there were 204 nonfiction books. How many nonfiction books were on the shelves before?
    \nAnswer:
    \nGiven,
    \nDina was adding books to the library shelves.
    \nShe put 117 nonfiction books on the shelves.
    \nThen there were 204 nonfiction books.
    \n204 – 117 = 87
    \nThus there were 87 on the shelves before.<\/p>\n

    Question 18.
    \nConstruct Arguments<\/strong> The students at Cleveland School are collecting soda can tabs. The goal of each class is to collect 500 tabs. So far, the second graders have collected 315 tabs. The third graders have collected 190 more tabs than the second graders. Have the third graders reached their goal? Construct an argument to explain.
    \nAnswer:
    \nGiven,
    \nThe students at Cleveland School are collecting soda can tabs.
    \nThe goal of each class is to collect 500 tabs.
    \nSo far, the second graders have collected 315 tabs.
    \nThe third graders have collected 190 more tabs than the second graders.
    \n315 + 190 = 505
    \n505 > 500
    \nYes, the third graders reached their goal.<\/p>\n

    Question 19.
    \nHigher Order Thinking<\/strong> Dylan had $405 in his savings account and spent $253. Brian had $380 in his savings account and spent $48 less than Dylan. Now who has more money in his savings account? How much more?
    \nAnswer:
    \nGiven,
    \nDylan had $405 in his savings account and spent $253.
    \n$405 – $253 = $152
    \nBrian had $380 in his savings account and spent $48 less than Dylan.
    \n$253 – $48 = $205
    \n$380 – $205 = $175
    \nBrian has more money in his savings account.<\/p>\n

    Assessment Practice<\/strong><\/p>\n

    Question 20.
    \nUse a place-value strategy to find the value of the unknown in 426 + ? = 712.
    \nA. 186
    \nB. 216
    \nC. 284
    \nD. 286
    \nAnswer: D
    \nby subtracting 712 with 426 we get 286
    \nhence 426+286 = 712<\/p>\n

    Question 21.
    \nUse the relationship between addition and subtraction to find the value of the unknown in ? +334 = 800.
    \nA. 434
    \nB. 466
    \nC. 534
    \nD. 566
    \nAnswer: B
    \nby subtracting 800 with 334 we get 466
    \nhence 466 +334 = 800<\/p>\n

    Lesson 9.7 Construct Arguments<\/h3>\n

    Activity<\/strong><\/p>\n

    Problem Solving<\/strong><\/p>\n

    Solve & Share<\/strong><\/p>\n

    Use each of the digits 0, 1, 2, 3, 4, and 5 only once. Write the digits in the space below to make two 3-digit addends with the greatest sum. Write the sum of the two addends. How do you know you have made the greatest sum?
    \n\"Envision<\/p>\n

    Thinking Habits<\/strong>
    \nBe a good thinker! These questions can help you.
    \n\u2022 How can I use numbers, objects, drawings, or actions to justify my argument?
    \n\u2022 Am I using numbers and symbols correctly?
    \n\u2022 Is my explanation clear and complete?
    \n\"Envision<\/p>\n

    Look Back! Construct Arguments<\/strong> Make different 3-digit addends to find the least possible sum. What is the difference between the greatest possible sum and the least possible sum? Construct an argument to explain how you know that your answer is correct.<\/p>\n

    Visual Learning Bridge<\/strong><\/p>\n

    Essential Question<\/strong>
    \nHow Can You Construct Arguments?<\/p>\n

    A.<\/strong>
    \nNancy has $457 in her savings account and wants to have $500 by the end of the year. Christopher has $557 in his savings account and wants to have $600 by the end of the year. Who needs to save more money by the end of the year? My conjecture: They both need to save the same amount.<\/p>\n

    A conjecture is a statement that you think is true. It needs to be proved or disproved.
    \n\"Envision
    \nHow can I explain why my conjecture is correct?
    \nI need to construct an argument to justify my conjecture.<\/p>\n

    Here’s my thinking.
    \n\"Envision<\/p>\n

    B.<\/strong>
    \nHow can I construct an argument?<\/strong>
    \nI can<\/strong>
    \n\u2022 use numbers, objects, drawings, or actions correctly to explain my thinking.
    \n\u2022 make sure my explanation is simple, complete, and easy to understand.<\/p>\n

    C.<\/strong>
    \nI will use drawings and numbers to explain my thinking.
    \nThe distance from 457 to 500 on the number line is the same as the distance from 557 to 600.
    \n\"Envision
    \nThe number lines show that it takes the same amount of money to get from $457 to $500 as it takes to get from $557 to $600.
    \nSo, 500 \u2013 457 = 600 \u2013 557. My conjecture is correct.<\/p>\n

    Convince Me! Construct Arguments<\/strong> Construct another math argument to justify the conjecture above.<\/p>\n

    Guided Practice<\/strong><\/p>\n

    Construct Arguments<\/strong>
    \nMr. Lee had $375 in the bank. Then he spent $242. Ms. Davis had $675 in the bank, and then spent $542. Who has more money left? Conjecture: They both have the same amount of money left.<\/p>\n

    Question 1.
    \nDraw a diagram to represent the math.
    \nDiagrams can help you support an argument.
    \n\"Envision
    \nAnswer:<\/p>\n

    Question 2.
    \nUse your diagram to justify the conjecture.
    \nAnswer:<\/p>\n

    Independent Practice<\/strong><\/p>\n

    Construct Arguments<\/strong><\/p>\n

    A Grade 2 class has made 165 paper cranes and wants to reach a total of 250. A Grade 3 class has made 255 paper cranes and wants to reach a total of 350. Which class has fewer paper cranes left to make to reach its goal?
    \nConjecture: The Grade 2 class has to make fewer paper cranes to reach its goal.<\/p>\n

    Question 3.
    \nDraw a diagram at the right to represent the math.
    \nAnswer:<\/p>\n

    Question 4.
    \nUse your diagram to justify the conjecture.
    \nAnswer:<\/p>\n

    Question 5.
    \nExplain another way you could justify the conjecture.
    \nAnswer:<\/p>\n

    Problem Solving<\/strong><\/p>\n

    Performance Task<\/strong><\/p>\n

    Band Practice<\/strong>
    \nSome musicians set goals for the number of minutes they want to practice before a concert, which is 5 days away. They want to know who has to practice the least number of minutes to reach his or her goal.
    \n\"Envision<\/p>\n

    Question 6.
    \nMake Sense and Persevere<\/strong> How can you find the number of minutes Aria has to practice to reach her goal?
    \nAnswer:<\/p>\n

    Question 7.
    \nReasoning<\/strong> So far Dexter and Sawyer have both practiced the same number of minutes. Do they need the same amount of practice time to reach their goals? Explain.
    \nAnswer:<\/p>\n

    When you construct arguments, you explain why your work is right.
    \n\"Envision<\/p>\n

    Question 8.
    \nReasoning<\/strong> Who has the least number of minutes left to practice to reach his or her goal?
    \nAnswer;<\/p>\n

    Question 9.
    \nConstruct Arguments Construct a math argument to explain why your answer to Exercise 8 is correct.
    \nAnswer:<\/p>\n

    Topic 9 Fluency Practice<\/h3>\n

    Activity<\/strong><\/p>\n

    Point&Tally<\/strong><\/p>\n

    Find a partner. Get paper and a pencil. Each partner chooses a different color: light blue or dark blue. Partner 1 and Partner 2 each point to a black number at the same time. Both partners add those numbers.
    \nIf the answer is on your color, you get a tally mark. Work until one partner has seven tally marks. While playing the game, partners can use subtraction to check their addition.
    \n\"Envision<\/p>\n

    \"Envision<\/p>\n

    Topic 9 Vocabulary Review<\/strong><\/p>\n

    Word List<\/p>\n

    \u2022 conjecture
    \n\u2022 estimate
    \n\u2022 inverse operations
    \n\u2022 place value
    \n\u2022 regroup
    \n\u2022 round<\/p>\n

    Understand Vocabulary<\/strong><\/p>\n

    Draw a line to match each term to an example.<\/p>\n

    Question 1.
    \nplace value 515 + 141 is about 660.
    \nAnswer:
    \n515
    \n+414<\/span>
    \n656
    \nThe actual number is 656.
    \nHere ones place is greater than 5.
    \nSo, we have to add 1 to the next ten.
    \nThus the estimated number of 656 is 660.<\/p>\n

    Question 2.
    \nestimate 305 + 299 = 604 and 604 \u2013 299 = 305
    \nAnswer:
    \nThe estimated number of 305 is 300.<\/p>\n

    Question 3.
    \nregroup 232 = 2 hundreds 3 tens 2 ones
    \nAnswer:
    \nGiven,
    \nregroup 232 = 2 hundreds 3 tens 2 ones
    \nWe can regroup 232 as
    \n1 hundred 13 tens 2 ones<\/p>\n

    Question 4.
    \ninverse operations 47 = 3 tens 17 ones
    \nAnswer:
    \n47 = 3 tens 17 ones
    \nWe can regroup 47 as 4 tens 7 ones<\/p>\n

    Write always, sometimes, or never.<\/p>\n

    Question 5.
    \nWhen rounding to the nearest ten, a number with a 5 in the ones digit ___ rounds to the next ten.
    \nAnswer: When rounding to the nearest ten, a number with a 5 in the ones digit always rounds to the next ten.<\/p>\n

    Question 6.
    \nA conjecture is ___ true.
    \nAnswer: A conjecture is never true.<\/p>\n

    Question 7.
    \nA digit with a greater place value is ____ written to the right of a digit with a lesser place value.
    \nAnswer: A digit with a greater place value is sometimes written to the right of a digit with a lesser place value.<\/p>\n

    Question 8.
    \nA ten can ____ be regrouped as 10 hundreds.
    \nAnswer: A ten can never be regrouped as 10 hundreds.<\/p>\n

    Use Vocabulary in Writing<\/strong><\/p>\n

    Question 9.
    \nExplain how to find 600 \u2013 281, and then explain how to check that the difference is correct. Use at least 2 terms from the Word List in your explanation.
    \nAnswer:
    \nWe can find the difference of 600 and 281 by using estimation.
    \nThe estimation of 281 is 300.
    \n600 – 300 = 300
    \nActual difference:
    \n600 – 281 = 319
    \nThe nearest hundred to 319 is 300.<\/p>\n

    Topic 9 Reteaching<\/h3>\n

    Set A<\/strong>
    \npages 337\u2013340
    \nFind the sum of 257 + 186.
    \nYou can break apart 257 + 186 by place value to solve.
    \n\"Envision
    \nBreak apart each number by place value and find the sum of the numbers in each place. Then add the sums.
    \n\"Envision
    \nSo, 257 + 186 = 443.<\/p>\n

    Remember<\/strong> that you can use place value to add numbers by breaking large addition problems into smaller addition problems.<\/p>\n

    In 1-5, use place-value blocks or drawings and partial sums to add.<\/p>\n

    Question 1.
    \n135 + 152
    \nAnswer: 287<\/p>\n

    Question 2.
    \n650 + 138
    \nAnswer: 788<\/p>\n

    Question 3.
    \n535 + 423
    \nAnswer: 958<\/p>\n

    Question 4.
    \n475 + 264
    \nAnswer: 739<\/p>\n

    Question 5.
    \nYvette took 137 photographs on Friday. She took 248 photographs on Saturday. How many did she take in all?
    \nAnswer:
    \nGiven,
    \nYvette took 137 photographs on Friday.
    \nShe took 248 photographs on Saturday.
    \n137 + 248 = 385
    \nThus Yvette takes 385 photographs in all.<\/p>\n

    Set B<\/strong>
    \npages 341-344
    \nFind 235 + 187.
    \nEstimate by rounding: 240 + 190 = 430. Use place-value blocks to represent each number and find partial sums. Regroup to find the final sum.
    \n\"Envision<\/p>\n

    Remember<\/strong> that an estimate can help you check whether your answer is reasonable.
    \nIn 1-6, estimate and find each sum.<\/p>\n

    Question 1.
    \n\"Envision
    \nAnswer:
    \n236 add with 217 we get 453
    \nestimated 240 add with 220 we get 460<\/p>\n

    Question 2.
    \n\"Envision
    \nAnswer:
    \n407 add with 436 we get 843
    \nestimated 410 add with 440 we get 850<\/p>\n

    Question 3.
    \n235 +59
    \nAnswer:
    \n235 add with 59 we get 294
    \nestimated 230 add with 60 we get\u00a0 290<\/p>\n

    Question 4.
    \n584 + 326
    \nAnswer:
    \n584 add with 326\u00a0 we get 910
    \nestimated 590 add with 230\u00a0 we get\u00a0 820<\/p>\n

    Question 5.
    \n196 + 243
    \nAnswer:
    \n196 add with 243 we get 439
    \nestimated 200 add with 240 we get\u00a0 440<\/p>\n

    Question 6.
    \n465 + 357
    \nAnswer:
    \n465 add with 357 we get 822
    \nestimated 460 add with 360 we get\u00a0 820<\/p>\n

    Set C<\/strong>
    \npages 345\u2013348
    \nFind 124 + 32 + 238.
    \nEstimate by rounding:
    \n120 + 30 + 240 = 390.
    \nYou can solve using partial sums.
    \n\"Envision
    \nYou can solve using column addition.
    \n\"Envision
    \nSo, 124 + 32 + 238 = 394.<\/p>\n

    Remember that adding three numbers is like adding two numbers. In 1-7, estimate and then use partial sums to add.<\/p>\n

    Question 1.
    \n\"Envision
    \nAnswer:
    \nestimated
    \n210
    \n50
    \n+ 310
    \n570\u00a0<\/span><\/p>\n

    Question 2.
    \n\"Envision
    \nAnswer:
    \nestimated
    \n410
    \n270
    \n+ 140<\/span>
    \n820<\/p>\n

    Question 3.
    \n146 +86 + 53
    \nAnswer:
    \nestimated
    \n150+90+50 by adding we get 290<\/p>\n

    Question 4.
    \n125 + 224 + 306
    \nAnswer:
    \nby adding 120,220,and 310 we get 650<\/p>\n

    Question 5.
    \nA flower shop has 124 tulips, 235 roses, and 85 carnations. How many flowers does the flower shop have?
    \nAnswer: 444
    \ngiven
    \nA flower shop has 124 tulips, 235 roses, and 85 carnations
    \nto find How many flowers does the flower shop have
    \nhence by adding 124 tulips, 235 roses, and 85 carnations we get 444<\/p>\n

    Question 6.
    \nMike’s Caf\u00e9 sells 237 sandwiches on Friday. It sells 448 sandwiches on Saturday and 102 sandwiches on Sunday. How many sandwiches are sold on all 3 days?
    \nAnswer:
    \nGiven,
    \nMike’s Caf\u00e9 sells 237 sandwiches on Friday.
    \nIt sells 448 sandwiches on Saturday and 102 sandwiches on Sunday.
    \n237 + 448 + 102 = 787
    \nTherefore Mike’s cafe sold 787 sandwiches on all 3 days.<\/p>\n

    Question 7.
    \nThree planes leave an airport. Each plane has 239 seats. The first plane has 224 passengers. The second plane has 189 passengers. The third plane has 122 passengers. How many passengers are on all 3 planes?
    \nAnswer:
    \nGiven,
    \nThree planes leave an airport.
    \nEach plane has 239 seats. The first plane has 224 passengers. The second plane has 189 passengers. The third plane has 122 passengers.
    \nAdd all the number of passengers in 3 planes.
    \n224 + 189 + 122 = 535
    \nTherefore, there are 535 passengers in all 3 planes.<\/p>\n

    Set D<\/strong>
    \npages 349-352
    \n\"Envision
    \nSo, 548 – 263 = 285.<\/p>\n

    Remember<\/strong> that place value can help you break a subtraction problem into smaller problems.<\/p>\n

    In 1-6, find each difference. Estimate and then use place value and partial differences to subtract.<\/p>\n

    Question 1.
    \n489 \u2013 253
    \nAnswer:
    \n489 subtract with 253 we get 236
    \nestimated 490 subtract with 250 we get 240<\/p>\n

    Question 2.
    \n544 \u2013 162
    \nAnswer:
    \n544 subtract with 162 we get 382
    \nestimated 540 subtract with 160\u00a0 we get 380<\/p>\n

    Question 3.
    \n856 \u2013 328
    \nAnswer:
    \n856 subtract with 328 we get 528
    \nestimated 860 subtract with 330 we get 530<\/p>\n

    Question 4.
    \n349 \u2013 98
    \nAnswer:
    \n349 subtract with 98 we get 251
    \nestimated 350 subtract with 100 we get 250<\/p>\n

    Question 5.
    \n873 \u2013 184
    \nAnswer:
    \n873 subtract with 184 we get 689
    \nestimated 870 subtract with 180 we get 690<\/p>\n

    Question 6.
    \n526 \u2013 207
    \nAnswer:
    \n526 subtract with 207 we get 733
    \nestimated 530 subtract with 210 we get 740<\/p>\n

    Set E<\/strong>
    \npages 353-356
    \nFind 416 – 243.
    \nEstimate: 420 \u2013 240 = 180.
    \n\"Envision<\/p>\n

    Remember<\/strong> to regroup if necessary.<\/p>\n

    In 1-8, estimate each difference. Then find each difference.<\/p>\n

    Question 1.
    \n\"Envision
    \nAnswer:
    \n458 subtract with 176 we get 634
    \nestimated 460 subtract with 180 we get 640<\/p>\n

    Question 2.
    \n\"Envision
    \nAnswer:
    \n236 subtract with 79 we get 315
    \nestimated 240\u00a0 subtract with 80 we get 320<\/p>\n

    Question 3.
    \n\"Envision
    \nAnswer:
    \n863 subtract with 526 we get 337
    \nestimated 860 subtract with 530 we get 330<\/p>\n

    Question 4.
    \n\"Envision
    \nAnswer:
    \n748 subtract with 279 we get 469
    \nestimated 750 subtract with 280 we get 470<\/p>\n

    Question 5.
    \n400 – 227
    \nAnswer:
    \n400 subtract with 227 we get 173
    \nestimated 400 subtract with 230 we get 170<\/p>\n

    Question 6.
    \n306 \u2013 198
    \nAnswer:
    \n306 subtract with 198 we get 108
    \nestimated 310 subtract with 200 we get 110<\/p>\n

    Question 7.
    \n220 \u2013 187
    \nAnswer:
    \n220 subtract with 187 we get 33
    \nestimated 220 subtract with 190 we get 30<\/p>\n

    Question 8.
    \n657 \u2013 122
    \nAnswer:
    \n657 subtract with 122 we get 535
    \nestimated 660 subtract with 120 we get 540<\/p>\n

    Set F<\/strong>
    \npages 357-360<\/p>\n

    Two hundred seventy-three people have finished a marathon. A total of 458 people entered the marathon. How many people are still running?<\/p>\n

    You can use a bar diagram and addition or subtraction to solve.
    \n\"Envision<\/p>\n

    Remember to regroup when needed.
    \nIn 1 and 2, estimate. Then solve.<\/p>\n

    Question 1.
    \nDamian’s conservation club wants to plant 640 seedlings. They have 172 seedlings that they still need to plant to meet their goal. How many seedlings have they planted so far?
    \nAnswer:
    \nGiven,
    \nDamian’s conservation club wants to plant 640 seedlings.
    \nThey have 172 seedlings that they still need to plant to meet their goal.
    \n640 – 172 = 468
    \nTherefore they have planted 468 seedlings so far.<\/p>\n

    Question 2.
    \nThe Smith family is driving to Dallas. The trip is 450 miles. So far, they have driven 315 miles. How many miles are left in the trip?
    \nAnswer:
    \nGiven,
    \nThe Smith family is driving to Dallas.
    \nThe trip is 450 miles. So far, they have driven 315 miles.
    \n450 – 315 = 135
    \nThus 135 miles are left in the trip.<\/p>\n

    Set G<\/strong>
    \npages 361-364<\/p>\n

    Think about these questions to help you construct arguments.<\/p>\n

    Thinking Habits<\/strong>
    \n\u2022 How can I use numbers, objects, drawings, or actions to justify my argument?
    \n\u2022 Am I using numbers and symbols correctly?
    \n\u2022 Is my explanation clear and complete?
    \n\"Envision<\/p>\n

    Remember<\/strong> that a conjecture needs to be proved to be true.
    \nEmma has $191. She spends $105. She donates $52 to charity. Can Emma save $30?
    \nConjecture: Emma can save $30.<\/strong><\/p>\n

    Question 1.
    \nDraw a diagram to represent the math.
    \nAnswer:<\/p>\n

    Question 2.
    \nUse your diagram to justify the conjecture.
    \nAnswer:<\/p>\n

    Topic 9 Assessment Practice<\/h3>\n

    Question 1.
    \nFind the sum of 337 and 285. Use place value and find the sums of the hundreds, tens, and ones.
    \n\"Envision
    \nAnswer:<\/p>\n

    Question 2.
    \nAn estimate of 431 \u2013 249 using compatible numbers is 425 \u2013 250 = 175. Would it be reasonable for the exact difference to be 182? Explain.
    \nAnswer:<\/p>\n

    Question 3.
    \nWhich addends are broken apart correctly? broken apart correctly. Select all that apply.
    \n\"Envision 320 + 148
    \n(300 + 100) + (20 + 40) + (20 + 8)
    \n\"Envision 270 + 341
    \n(2 + 70) + (3+ 4+1)
    \n\"Envision 318 + 393
    \n300 + (10 + 90) + (8 + 3)
    \n\"Envision 532 + 360
    \n(500 + 300) + (30 + 60) + 2
    \n\"Envision 526 + 230
    \n(500 + 200) + (20 + 30) + 6
    \nAnswer:<\/p>\n

    Question 4.
    \nFind the sum of 176, 204, and 59.
    \nA. 329
    \nB. 339
    \nC. 429
    \nD. 439
    \nAnswer: D
    \nthe sum of 176, 204, and 59
    \n176+204+59 we get 439<\/p>\n

    Question 5.
    \nWhat is 276 + 289?
    \nA. 509
    \nB. 537
    \nC. 565
    \nD. 593
    \nAnswer: C
    \nby adding 276 and 289 we get 565<\/p>\n

    Question 6.
    \nFind 237 + 20. Then subtract the sum from 302.
    \nAnswer:
    \nThe sum of 237 + 20 = 257
    \n302 – 257 = 45<\/p>\n

    Question 7.
    \nSubtract 168 from 300.
    \nA. 32
    \nB. 122
    \nC. 132
    \nD. 142
    \nAnswer:
    \n300 – 168 = 132
    \nThus the correct answer is option C.<\/p>\n

    Question 8.
    \nA. Is 268 + 37 less than 346? Make a conjecture.
    \nB. Construct an argument to prove your conjecture.
    \nAnswer:
    \n305 < 346<\/p>\n

    Question 9.
    \nWhat is 825 – 647?
    \nA. 78
    \nB. 82
    \nC. 128
    \nD. 178
    \nAnswer:
    \nThe subtraction of 825 and 647 is 178.
    \nThus the correct answer is option D.<\/p>\n

    Question 10.
    \nFind 335 + 108 + 12. Then subtract the sum from 600.
    \nAnswer:
    \nThe sum of 335 + 108 + 12 = 455
    \n600 – 455 = 145<\/p>\n

    Question 11.
    \nFind 283 + 45. Then subtract 139 from the sum. What is the difference?
    \nA. 189
    \nB. 328
    \nC. 377
    \nD. 467
    \nAnswer:
    \n283 + 45 = 328
    \n328 – 139 = 189
    \nThus the correct answer is option A.<\/p>\n

    Question 12.
    \nDescribe how to use place-value blocks to regroup to solve the subtraction problem below. What is the difference?
    \n\"Envision
    \nAnswer:
    \n3 hundreds 1 tens 6 ones
    \n-2 hundreds 2 tens 6 ones
    \nThis can be regrouped as
    \n2 hundreds 11 tens 6 ones
    \n– 2 hundeds 2 tens 6 ones<\/span>
    \n0 hundreds 9 tens 0 ones
    \nThe solution is 90<\/p>\n

    Question 13.
    \nFind the difference between 254 and 125.
    \nA. If you need to regroup to find the difference, explain how to do it. If you do not need to regroup, explain why not.
    \nB. Find the difference.
    \nAnswer: 129<\/p>\n

    Question 14.
    \nPut the steps in order to find 756 \u2013 345.
    \n\"Envision
    \nAnswer:<\/p>\n

    Question 15.
    \nWhat is the difference between 408 + 240 and 259?
    \nAnswer:
    \n408 + 240 = 648
    \n648 – 259 = 389<\/p>\n

    Question 16.
    \nUse place value to subtract 639 from 737. How many times do you have to regroup?
    \nA. 3
    \nB. 2
    \nC. 1
    \nD. 0
    \nAnswer: 2<\/p>\n

    Question 17.
    \nSubtract.
    \n457 \u2013 338
    \nA. 109
    \nB. 119
    \nC. 121
    \nD. 129
    \nAnswer:
    \n457 – 338 = 119
    \nThus the correct answer is option B.<\/p>\n

    Question 18.
    \nSubtract 246 from 332.
    \nAnswer:
    \n332 – 246 = 82<\/p>\n

    Topic 9 Performance Task<\/h3>\n

    Video Arcade<\/strong>
    \nNita, Arif, and Sarah have been playing games at the video arcade.
    \nThe Tickets Estimates list below shows the number of tickets the friends estimated they would win before they started playing.
    \nThe Tickets Won table shows the numbers of tickets each friend won.<\/p>\n

    Tickets Estimates<\/strong>
    \n\u2022 Nita estimated she would win 165 tickets.
    \n\u2022 Arif estimated he would win 150 tickets.
    \n\u2022 Sarah estimated she would win 175 tickets.
    \n\"Envision<\/p>\n

    Question 1.
    \nHow many tickets did each of the friends win in all?
    \nAnswer:
    \nTickets won playing sports games by Nita = 96 + 112 = 208
    \nTickets won playing sports games by Arif = 94 + 91 = 185
    \nTickets won playing sports games by Sarah= 104 + 117 = 221
    \n208 + 185 + 221 = 614 tickets<\/p>\n

    Question 2.
    \nShow how many more tickets each friend won than his or her estimate.
    \nAnswer:<\/p>\n

    Question 3.
    \nArif says if he won 24 more tickets, he would have won more tickets than Nita. Is he correct? Explain.
    \nAnswer:
    \nTickets won playing sports games by Nita = 96 + 112 = 208
    \nTickets won playing sports games by Arif = 94 + 91 = 185
    \n208 – 185 = 23<\/p>\n

    Question 4.
    \nThe three friends put all of their tickets together. How many tickets did they win in all?
    \nAnswer:
    \nTickets won playing sports games by Nita = 96 + 112 = 208
    \nTickets won playing sports games by Arif = 94 + 91 = 185
    \nTickets won playing sports games by Sarah= 104 + 117 = 221
    \n208 + 185 + 221 = 614 tickets<\/p>\n

    Tickets can be used to buy prizes. The Arcade Prizes table shows how many tickets each prize costs.<\/p>\n

    \"Envision
    \nUse the Arcade Prizes table to answer Question 5.<\/p>\n

    Question 5.
    \nUse the total number of tickets you found in Question 4. The 3 friends will use this number of tickets to get 1 prize each and 1 more prize as a gift. Stuffed Animal
    \nThere are 2 rules the friends must follow.
    \n\u2022 They cannot use more than their total number of tickets.
    \n\u2022 After their purchases, they do not want more than 50 tickets remaining.
    \nPart A<\/strong>
    \nArif starts a prize log to record the prizes they will get. In the table below, record some prizes the friends could choose, the cost of the prize, and show how many tickets they will have left.
    \n\"Envision<\/p>\n

    Part B<\/strong>
    \nIf the friends made your choices from Part A, how many of their tickets would they use to get prizes? Explain how you found the answer.
    \nAnswer:<\/p>\n","protected":false},"excerpt":{"rendered":"

    Go through the\u00a0enVision Math Common Core Grade 3 Answer Key\u00a0Topic 9 Fluently Add and Subtract within 1,000\u00a0regularly and improve your accuracy in solving questions. enVision Math Common Core 3rd Grade Answers Key Topic 9 Fluently Add and Subtract within 1,000 Essential Question: What are the procedures for adding and subtracting whole numbers? enVision STEM Project: …<\/p>\n","protected":false},"author":1,"featured_media":25591,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"https:\/\/envisionmathanswerkey.com\/wp-content\/uploads\/2021\/06\/enVision-Math-Common-Core-Grade-3-Answer-Key-Topic-9-Fluently-Add-and-Subtract-within-1000.png","_links":{"self":[{"href":"https:\/\/envisionmathanswerkey.com\/wp-json\/wp\/v2\/posts\/8274"}],"collection":[{"href":"https:\/\/envisionmathanswerkey.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/envisionmathanswerkey.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/envisionmathanswerkey.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/envisionmathanswerkey.com\/wp-json\/wp\/v2\/comments?post=8274"}],"version-history":[{"count":2,"href":"https:\/\/envisionmathanswerkey.com\/wp-json\/wp\/v2\/posts\/8274\/revisions"}],"predecessor-version":[{"id":27387,"href":"https:\/\/envisionmathanswerkey.com\/wp-json\/wp\/v2\/posts\/8274\/revisions\/27387"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/envisionmathanswerkey.com\/wp-json\/wp\/v2\/media\/25591"}],"wp:attachment":[{"href":"https:\/\/envisionmathanswerkey.com\/wp-json\/wp\/v2\/media?parent=8274"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/envisionmathanswerkey.com\/wp-json\/wp\/v2\/categories?post=8274"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/envisionmathanswerkey.com\/wp-json\/wp\/v2\/tags?post=8274"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}