Envision Math 5th Grade Textbook Answer Key Topic 2 Reteaching Set A, pages 24-26 Add 53 + 11 + 7 using mental math. 53 and 7 are compatible numbers, and the Commutative Property of Addition allows you to add in any order. 53 + 11 + 7 = 53 + 7 + 11 = 60 + 11 = 71 Remember that you can use compatible numbers or compensation to find sums and differences. Question 1. 67 + 28 Answer: Question 2. 130 + 470 Answer: Question 3. 35 + 14 + 6 Answer: Question 4. 276 – 99 Answer: Question 5. 96 + 234 + 4 Answer: Set B, pages 28–29 Round 12.087 to the underlined place. 12.087 Look at the digit following the underlined digit. Look at 7. Round the 8 to the next higher digit because 7 > 5. 12.087 is about 12.09. Remember that rounding a number means replacing it with another number that tells about how much or how many. Question 1. 10.245 Answer: Question 2. 9.145 Answer: Question 3. 67,901 Answer: Question 4. 99,102 Answer: Set C, pages 30–32 Estimate 19.9 + 17.03 19.9 + 17.03 is about 37. Remember that you can also use…

## Envision Math Grade 5 Answer Key Topic 2 Test Prep

Envision Math 5th Grade Textbook Answer Key Topic 2 Test Prep Test prep Question 1. The Chen family’s home has 1,515 square feet downstairs and 625 square feet upstairs. Which of the following is the best estimate of the total square footage in the home? (2-3) A. 2,100 B. 2,200 C. 2,300 D. 2,500 Answer: Question 2. What is 2.934 rounded to the nearest hundredth? (2-2) A. 2.90 B. 2.93 C. 2.94 D. 3.00 Answer: Question 3. Eduardo is training for a marathon. He ran his first mile in 12.567 minutes and his second mile in 12.977 minutes. What is his combined time for the first two miles? (2-5) A. 24.434 minutes B. 24.544 minutes C. 25.444 minutes D. 25.544 minutes Answer: Question 4. To add 18 + 25 using mental math, Braxton did the following. What is the missing number that makes the statement true? A. 43 B. 25 C. 20 D. 2 Answer: Question 5. Which two trails combined are less than 4 miles? Use estimation to decide. (2-3) A. Red and Yellow B. Blue and Green C. Red and Green D. Blue and Yellow Answer: Question 6. The Thomas Jefferson Memorial is on 18.36 acres of land…

## Envision Math Grade 5 Answer Key Topic 2.7 Problem Solving

Envision Math 5th Grade Textbook Answer Key Topic 2.7 Problem Solving Problem Solving Draw a Picture and Write an Equation Three friends have music collections. How many more CDs does Susan have than Larry? Another Example Rori had some balloons and then gave 35 of them away. She now has 21 left. How many balloons did Rori have to begin with? One Way Think The total is unknown. 35 were given away and 21 are left. Write an Equation x – 35 = 21 21 + 35 = 56, so 56 is the total. x = 56 Another Way Think 35 were given away. Rori has 21 left. The total is unknown. Write an Equation 35 + 21 = x 35 + 21 = 56, so 56 is the total. x = 56 Rori had 56 balloons to begin with. Explain It Question 1. Why do both ways use addition to solve for x? Answer: Question 2. How can you check if 56 is a reasonable answer? Answer: Read and Understand What do I know? Susan has 42 CDs and Larry has 26 CDs. What am I asked to find? The difference between the number of CDs from these two…

## Envision Math Grade 5 Answer Key Topic 2.6 Subtracting Decimals

Envision Math 5th Grade Textbook Answer Key Topic 2.6 Subtracting Decimals Subtracting Decimals How can you subtract decimals? What is the difference in the wingspans of the two butterflies? Choose an Operation Subtract to find the difference. Find 5.92 – 4.37. Estimate: 6 – 4 = 2 Other Examples Using 0 as a placeholder Find 49.59 – 7.9 Using 0 as a placeholder Find 24.6 – 8.27. Subtracting Money Find $26.32 – $5.75. Guided Practice* In 1 through 8, subtract the decimals. Do you know how? Question 1. Answer: Question 2. Answer: Question 3. Answer: Question 4. Answer: Question 5. 56.8 – 2.765 Answer: Question 6. $43.80 – $16.00 Answer: Question 7. 22.4 – 10.7 8. Answer: Question 8. $36.40 – $21.16 Answer: Do you understand? Question 9. Reasonableness Explain why 1.55 cm is a reasonable answer for the difference in the wingspans of the two butterflies. Answer: Question 10. In the Other Examples above, is the value of 7.9 changed when you annex a zero after 7.9? Why or why not? Answer: Question 11. Writing to Explain How is finding 9.12 – 4.8 similar to finding $9.12 – $4.80? How is it different? Step 1 Write the numbers, lining…

## Envision Math Grade 5 Answer Key Topic 2.5 Adding Decimals

Envision Math 5th Grade Textbook Answer Key Topic 2.5 Adding Decimals Adding Decimals How can you add decimals? What was the combined time for the first two legs of the relay race? Choose an Operation Add to join groups. Find 21.49 + 21.59. Estimate: 21 + 22 = 43 Guided Practice* Do you know HOW? In 1 through 6, add the decimals. Question 1. 0.82 + 4.21 Answer: Question 2. 9.1 + 7.21 Answer: Question 3. 9.7 + 0.24 Answer: Question 4. 3.28 + 6.09 Answer: Question 5. 0.26 + 8.3 Answer: Question 6. 4.98 + 3.02 Answer: Do you UNDERSTAND? Question 7. Reasonableness How do you know the total time for the first two legs of the race is reasonable? Answer: Question 8. Writing to Explain How is finding $4.25 + $3.50 like finding 4.25 + 3.5? How is it different? Answer: Independent Practice In 9 through 26, add the decimals. Question 9. Answer: Question 10. Answer: Question 11. Answer: Question 12. Answer: Question 13. Answer: Question 14. Answer: Question 15. Answer: Question 16. Answer: Question 17. Answer: Question 18. Answer: Question 19. Answer: Question 20. Answer: Question 21. $271.90 + $34.22 22. Answer: Question 22. 658.2 + 0…

## Envision Math Grade 5 Answer Key Topic 2.4 Adding and Subtracting

Envision Math 5th Grade Textbook Answer Key Topic 2.4 Adding and Subtracting Adding and Subtracting How can you add and subtract whole numbers? What was the total number of motor vehicles made in the United States and Japan in one year? Choose an Operation Add to join groups. Find 11,989,387 + 10,511,518. Estimate: 12,000,000 + 11,000,000 = 23,000,000 Another Example How can you subtract across zeros? Find 5,002 – 2,684. Since addition and subtraction have an inverse relationship, check your subtraction by adding Step 1 Step 2 Check Explain It Question 1. Explain the regrouping in Step 1 of the subtraction example above. Answer: Question 2. Why can you check a subtraction problem by adding? Answer: Step 1 Line up numbers by place value. Add the ones, tens, and hundreds. Step 2 Continue adding. Regroup if needed. Insert commas in the sum to separate periods. The sum is reasonable since the estimate was 23,000,000. In one year a total of 22,500,905 vehicles were made Guided Practice* Do you know HOW? Add. Question 1. 5,741 + 31,018 Answer: Question 2. 7,110 + 499 Answer: Subtract. Question 3. 9,234 – 2,387 Answer: Question 4. 110,652 – 8,600 Answer: Do you UNDERSTAND? Question…

## Envision Math Grade 5 Answer Key Topic 2.3 Estimating Sums and Differences

Envision Math 5th Grade Textbook Answer Key Topic 2.3 Estimating Sums and Differences How can you estimate sums? Students are collecting cans of dog food to give to an animal shelter. Estimate the sum of the cans collected in Weeks 3 and 4. Another Example How can you estimate differences? Estimate 22.8 – 13.9. One Way Round each addend to the nearest whole number. 22.8 – 13.9 is about 9. Another Way Substitute compatible numbers. 22.8 – 13.9 is about 10. Explain It Question 1. Which estimate is closer to the actual difference? How can you tell without subtracting? Answer: Question 2. When is it appropriate to estimate an answer? Answer: Guided Practice* Do you know HOW? In 1 through 6, estimate the sums and differences. Question 1. 49 + 22 Answer: Question 2. 86 – 18 Answer: Question 3. 179 + 277 Answer: Question 4. 232 – 97 Answer: Question 5. 23.8 – 4.7 Answer: Question 6. 87.2 + 3.9 Answer: Do you UNDERSTAND? Question 7. Give an example of when estimating is useful. Answer: Question 8. The students in the example at the top collected more cans of dog food in week 4 than in week 3. Estimate…

## Envision Math Grade 5 Answer Key Topic 2.2 Rounding Whole Numbers and Decimals

Envision Math 5th Grade Textbook Answer Key Topic 2.2 Rounding Whole Numbers and Decimals How can you round whole numbers and decimals? Rounding replaces one number with another number that tells about how many or how much. Round 634 to the nearest hundred. Another Example How do you round 2.36 to the nearest tenth? Is 2.36 closer to 2.3 or 2.4? Think Is 2.36 closer to 2.3 or 2.4? Step 1 Find the rounding place. Look at the digit to the right of the rounding place. 2.36 Step 2 If the digit is 5 or greater, add 1 to the rounding digit. If the digit is less than 5, leave the rounding digit alone. Since 6 > 5, add 1 to the 3. Step 3 Drop the digits to the right of the rounding digit. 2.36 rounds to 2.4 Guided Practice* Do you know HOW? In 1 through 6, round each number to the place of the underlined digit. Question 1. 16 Answer: Question 2. 56.1 Answer: Question 3. 1.32 Answer: Question 4. 427,841 Answer: Question 5. 1,652 Answer: Question 6. 582,062 Answer: Do you UNDERSTAND? Question 7. To round 7,458 to the nearest hundred, which digit do you look…

## Envision Math Grade 5 Answer Key Topic 2.1 Mental Math

Envision Math 5th Grade Textbook Answer Key Topic 2.1 Mental Math Review What You Know Vocabulary Choose the best term from the box. Question 1. Using the ___ you can add two numbers in any order. Answer: Question 2. The ___ is the answer to a subtraction problem. Answer: Question 3. When you can change the grouping of numbers when adding you are using the ___. Answer: Question 4. The answer in an addition problem is called the ___. Rounding Round each number to the nearest hundred. Question 5. 748 Answer: Question 6. 293 Answer: Question 7. 139 Answer: Round each number to the nearest thousand. Question 8. 3,857 Answer: Question 9. 2,587 Answer: Question 10. 2,345 Answer: Round each number to the underlined digit. Question 11. 84.59 Answer: Question 12. 2.948 Answer: Question 13. 3.0125 Answer: Estimating Writing to Explain Write an answer for the question. Question 14. Explain how to use rounding when estimating Mental Math How can you use mental math to add and subtract? Jon bought 3 items. Properties of addition can help him find the sum of the cost. Another Example How can you use compensation to add or subtract? Sometimes you can change an…

## Envision Math Grade 5 Answer Key Topic 1 Reteaching

Envision Math 5th Grade Textbook Answer Key Topic 1 Reteaching Reteaching Set A, pages 4-5 Write the word form and tell the value of the underlined digit for 930,365. Nine hundred thirty thousand, three hundred sixty-five. Since the 0 is in the thousands place, its value is 0 thousands or 0. Write the word form and tell the value of the underlined digit for 65,467,386,941. Sixty-five billion, four hundred sixty-seven million, three hundred eighty-six thousand, nine hundred forty-one Since the 6 is in the ten billions place, its value is 60,000,000,000. Remember that, starting from the right, each group of three digits forms a period. Periods are separated by commas. Write the word form and tell the value of the underlined digit. Question 1. 9,000,009 Answer: Question 2. 300,000,000,000 Answer: Question 3. 25,678 Answer: Question 4. 17,874,000,000 Answer: Question 5. 4,000,345,000 Answer: Question 6. 105,389 Answer: Question 7. 876,400,000,00 Answer: Question 8. 600,309,470 Answer: Question 9. 135,000 Answer: Question 10. 2,647,000 Answer: Question 11. 4,104,327,894 Answer: Set B, pages 6-8 Write <, >, or = for in 2,876,547 2,826,547. Line up the numbers above one another. 2,876,547 Begin at the left and compare. 2,826,547 Notice that the ten thousands are…