Go through the enVision Math Common Core Grade 2 Answer Key Topic 10 Add Within 1,000 Using Models and Strategies regularly and improve your accuracy in solving questions.

## enVision Math Common Core 2nd Grade Answers Key Topic 10 Add Within 1,000 Using Models and Strategies

enVision STEM Project: Building Up to 1,000

Find Out Use drinking straws and pieces of tape. The total number of straws and pieces of tape cannot be more than 1,000. First, decide how many of each to use. Then share. Build the tallest buildings you can.
Journal: Make a Book Describe your building in a book. In your book, also:

• Tell how many drinking straws and pieces of tape you used.
• Tell how you would make a better building if you did it again.

Review What You Know

Vocabulary

Question 1.
Circle all of the hundreds digits in the numbers below.

Explanation:
The digit place
Thousands   Hundreds   Tens  Ones
5                0       2
5       8
1              0                0       0
5 and 0 are in the hundreds place and these values are circled.

Question 2.
Write the expanded form of the number.
846
____
800 + 40 + 6 is the expanded form of 846.
Explanation:
Given number is a three digit number
8 in Hundreds place
4 in Tens place
6 in Ones place

Question 3.
Write the word form of the number.
265
_____
265 = Two hundred and sixty five.
Explanation:
Given number is a three digit number
2 in Hundreds place
6 in Tens place
5 in Ones place

Open Number Lines

Question 4.
Use the open number line to find the sum.

54 + 13 = ___
54 + 13 = 67

Mental Math

Question 5.
Use mental math to find each sum.
40 + 37 = ____
6 + 77 + 4 = ___
40 + 37 = 40 + (30 + 7) = (40 + 30) + 7 = 70 + 7 = 77.
6 + 77 + 4 = (6 + 4) + 77 = 10 + 77 = 87.
Explanation:
Mental math we break the number of one addend and then giving park of one addend to the other addend.
Here in 40 + 37
we break 37 as 30 + 7
now we add 40 + 30 =70 + 7 = 77.
This simplify the adding of numbers.
In 2nd Sum
6 + 77 + 4
we add 6 + 4 =10 and then 10 + 77 = 87.

Partial Sums

Question 6.

Explanation:
Using partial sum
we add the place values of the numbers separately.
Hundreds place value + Hundreds place value
Tens place value + Tens place value
Ones place value + Ones place value
Here
46 + 53 = (40+50) + (6 + 3) = 90 + 9 = 99
29 + 61 = (20 + 60) + (9 + 1) = 80 + 10 = 90.

pick a Project

PROJECT 10A

What are the run times of two of your favorite movies?
Project: Write Movie Reviews

PROJECT 10B

How many shots do basketball teams block?

PROJECT 10C
How many miles are between a State Capital and other cities?
Project: Draw a State Map

PROJECT 10D
How far can people hike in the Sierra Nevada Mountains?
Project: Create a Hiking Guide

### Lesson 10.1 Add 10 and 100

Solve & Share

Activity

Forest Park Nursery sells trees.
Sal buys a maple tree for $125. A spruce free costs$10 more than a maple tree. An elm tree costs $100 more than a maple tree. What is the cost of a spruce tree? An elm tree? Use dollar bills, place-value blocks, or mental math to solve. Be ready to explain how you solved the problem. Visual Learning Bridge Convince Me! Use mental math to find 567 + 10 and 567 + 100. Explain your reasoning. Guided Practice Add. Use place-value blocks or mental math. Question 1. Answer: Question 2. Answer: Explanation: The square cube represents 100 square and hundreds place cube stick represents 10 cubes and tens place single cube represents 1 cube and ones place. In the above image (4 square cube + 1 cube stick + 2 cubes) + 1 cube stick (400 + 10 + 2) + 10 Adding tens place 10 +10 = 20 the value of the image = 400+20+2=422. Question 3. Answer: Explanation: The square cube represents 100 square and hundreds place cube stick represents 10 cubes and tens place single cube represents 1 cube and ones place. In the above image (3 square cube + 2 square cube) + 1 square cube (300 + 200) + 100 Adding hundreds place 500 + 100 = 600 the value of the image = 500 + 100 = 600. Question 4. Answer: Explanation: The square cube represents 100 square and hundreds place cube stick represents 10 cubes and tens place single cube represents 1 cube and ones place. In the above image (2 square cube + 5 cube stick + 3 cubes) + 1 Square cube (200 + 50 + 3) + 100 Adding Hundreds place values 200 + 100 = 300 the value of the image = 400+20+2=422. Independent Practice Add. Use place-value blocks or mental math. Question 5. 164 + 100 = Answer: Using mental math 164 + 100 Dividing 164 into smaller parts = (100 + 64 ) + 100 Now adding hundreds place values 100 + 100 = 200 200 + 64 = 264. Sum = 264. Question 6.$837 + $10 = ___ Answer: Using mental math 837 + 10 Dividing 837 into smaller parts (800 + 30 + 7 ) + 10 Adding tens places 30 + 10 = 40 800+40+7 = 847. Sum =$847.

Question 7.
329 + 100 = ___
Using mental math
329 + 100
Dividing 329 into smaller parts
(300+ 20 + 9) + 100
300+ 100 = 400
400+20+9 = 429
Sum = 429.

Question 8.
610 + 10 = ___
Dividing 610 into its smaller values
(600 + 10 ) + 10
10+10 = 20
= 600 + 20 =  620.
Sum = 620.

Question 9.
295 + 10 = ___

Question 10.
$497 +$100 = ___

Question 11.
790 + 10 = ___
Dividing 790 into its smaller values
(700 + 90 ) + 10
90+10 = 100
= 700 + 100 =  800.
Sum = 800.

Question 12.
693 + 100 = ___
Dividing 693 into its smaller values
(600 + 90 + 3 ) + 100
6 + 1 = 7
= 600 + 100 =  700.
= 700 + 90 + 3
= 793
Sum = 793.

Question 13.
900 + 100 = ___

Question 14.
460 + 10 = ___
Dividing 460 into its smaller values
(400 + 60 ) + 10
6 + 1 = 7
= 60 + 10 =  70.
=400 + 70
= 470
Sum = 470.

Question 15.
185 + 10 = ___
Dividing 185 into its smaller values
(100 + 80 + 5 ) + 10
8 + 1 = 9
= 80 + 10 =  90.
=100 + 90 + 5
= 195
Sum = 195.

Question 16.
723 + 100 = ___
Dividing 723 into its smaller values
(700 + 20 + 3 ) + 100
7 + 1 = 8
= 700 + 100 =  800.
= 800 + 20 + 3
= 823
Sum = 823.

Algebra Find the missing numbers. Use mental math to solve.

Question 17.
572 + = 672
Given
Sum 672
Both are 3-digit number
Hundred  Tens  Ones
5              7        2
6              7        2
The values in the tens place and ones place are same but the values in the hundreds place are different
Subtract the hundreds place values
6 – 5 = 1
600 – 500 = 100.
572 + 100 = 672.

Question 18.
285 + = 385
Given
Sum 385
Both are 3-digit number
Hundred  Tens  Ones
2              8        5
3              8        5
The values in the tens place and ones place are same but the values in the hundreds place are different
Subtract the hundreds place values
3 – 2 = 1
300 – 200 = 100.
285 + 100 = 385.

Question 19.
709 = 699 +
Given
Sum 709
Both are 3-digit number
Hundred  Tens  Ones
6              9       9
7              0       9
The values in the  ones place are same but the values in the tens and hundreds place are different
Adding 1 to  the tens place values
9 + 1 = 10
Now the value in the tens place is 0 and 1 is carried to the hundreds place
1 is added to hundreds place vale
6 + 1 = 7
10 is the missing number.
699 + 10 = 709.

Question 20.
422 = 322 +
Given
Sum 322
Both are 3-digit number
Hundred  Tens  Ones
4              2        2           – Sum
The values in the tens place and ones place are same but the values in the hundreds place are different
Subtract the hundreds place values
4 – 3 = 1
400 – 300 = 100.
322 + 100 = 422.

Question 21.
615 + = 625
Given
Sum 709
Both are 3-digit number
Hundred  Tens  Ones
6              2       5       – Sum
The values in the  ones place and hundreds place are same but the values in the tens are different
subtracting   the tens place values
2 – 1 = 1
1 + 1 = 2
10 is the missing number.
615 + 10 = 625.

Question 22.
600 = + 590
Given
Sum 600
Both are 3-digit number
Hundred  Tens  Ones
5              9       0
6              0        0
The values in the  ones place are same but the values in the tens and hundreds place are different
9 + 1 = 10
Now the value in the tens place is 0 and 1 is carried to the hundreds place
1 is added to hundreds place vale
5 + 1 = 6
10 is the missing number.
590 + 10 = 600.

Problem Solving

Solve each problem. Show your work.

Question 23.
enVision® STEM The Science Club asked 178 people about recycling. The club wants to ask a total of 188 people about recycling. How many more people will the Science Club need to ask?
___ more people
Number of people The Science Club asked about recycling = 178 people
Total number of people The Science Club wants to ask about recycling = 188 people.
Number of more people  The Science Club need to ask = 188 – 178 = 10.
10 more people.
Th given number is 3 digit number
Hundred place   Tens place   Once place
1                      8                   8
1                      7                   8
The Hundreds place value and ones place values are same. but the tens place value is different
8 – 7 = 1
80 – 70 = 10.
10 more people.

Question 24.
Use Structure Jordan has four $100 bills, three$20 bills, one $10 bill, and seven$1 bills. What will Jordan’s total be if Jayla gives him one more $10 bill? What will his total be if she gives him one more$100 bill?

Number of $100 bills Jordan has = 4 Number of$20 bills Jordan has = 3
Number of $10 bills Jordan has = 1 Number of$1 Jordan has = 7
Number of $10 bills Jayla gave to Jordan = 1 Total money Jordan have after adding Jayla’s$10 bill = $400 +$60 + $10 +$10 + $7 =$487
Jayla gave more $100 bill to Jordan Total money Jordan have after adding 1 more$100 bill = $487 +$100 = $587. The value of the hundreds place = 4 adding 1 4 + 1 = 5. The value of the hundreds place is 5. The remaining values remain same. Total money Jordan has =$587.

Question 25.
Higher Order Thinking Think of a 3-digit number. Write a story about adding 100 to your number. Then write an equation to show your solution.

A hotel has 250 rooms. Their is an event organized at the hotel the hotel is booked completely. Before the day of event there are 150 rooms filled. How many rooms need to be filled?
Number of room filled = 150
Total number of rooms in the hotel = 250
Number of more rooms to be filled = 250 – 150 = 100 rooms.
100 more rooms need to be filled.
Here the tens and ones place values are same but the Hundreds place value is different.
2 – 1 = 1
The difference in the hundreds place value is 1.
The difference is 100.

Question 26.
Assessment Practice Which equations are true? Choose all that apply.
$251 +$10 = $351 528 + 100 = 628 528 + 10 = 538$251 + $100 =$351
The Equations that are true are
2. 528 + 100 = 628
5 + 1 = 6
Sum = 528 + 100 =  628
3. 528 + 10 = 538
2 + 1 = 3
Sum = 528 + 10 = 538.
4. $251 +$100 = $351 Adding the hundreds place values 2 + 1 = 3 Sum =$251 + $100 =$351

### Lesson 10.2 Add on an Open Number Line

Activity

Solve & Share

Use the open number line to find 598 + 123. Explain your work.

Visual Learning Bridge

Convince Me!
Explain how you can use an open number line to find 599 + 205.

Guided Practice
Use an open number line to find each sum.

Question 1.
375 + 118 = ___

Explanation:
Here we are breaking the addend into hundreds , tens, ones which does not change its value.
The equation is 375 + 118
118 = 100+ 10+5+3
375+100=475
475+10 = 485
485+  5 =   490
490 + 3=  493
375 +118 = 493.

Question 2.
670 + 232 = ___

Explanation:
Here we are breaking the addend into hundreds , tens, ones which does not change its value.
The equation is 670 + 232
232 = 100+ 100 + 20 + 10 + 2
670 +100 = 770
770 +100 = 870
870 + 20 = 890
890 + 10 = 900
900 + 2 =  902
670 + 232 = 902.

Independent Practice
Use an open number line to find each sum.

Question 3.
269 + 156 = ___

Explanation:
Here we are breaking the addend into hundreds , tens, ones which does not change its value.
The equation is 269 + 156
156 = 100 + 20 + 20 + 10 + 5 + 1
269 + 100 = 369
369 + 20 = 389
389 + 20 = 409
409 + 10 =  419
419 + 5 = 424
424 + 1 = 425

Question 4.
637 + 242 = ___

Explanation:
Here we are breaking the addend into hundreds , tens, ones which does not change its value.
The equation is 637 + 242
242 = 100+ 100 + 20 + 20 + 2
637 +100 = 737
737 +100 = 837
837 + 20 = 857
857 + 20 = 877
877 + 2 = 879
637 + 242 = 879.

Question 5.
886 + 114 = ___

Explanation:
Here we are breaking the addend into hundreds , tens, ones which does not change its value.
The equation is 886 + 114
114 = 100+ 10 + 4
886 +100 = 986
986 +10 = 996
996 + 4 = 1000
886 + 114 = 1000.

Question 6.
208 + 598 =

Explanation:
Here we are breaking the addend into hundreds , tens, ones which does not change its value.
The equation is 208 + 598
598 = 100+ 100 + 100 + 100 + 100 + 50 + 40 + 5 + 3
598 = 500 + 50+ 40 + 5 + 3
208 + 100 = 308
308 + 100 = 408
408 + 100 = 508
508 + 100 = 608
608 + 100 = 708
708 + 50 = 758
758 + 40 = 798
798 + 5 = 803
803 + 3 = 806

Question 7.
Higher Order Thinking Lisa finds 550 + 298 using the open number line below. Is her work correct? Explain.

No, Lisa work is not correct as of addition expression.
The correct way is as below
550 + 298
breaking the addend 298 into hundreds , tens, ones
298 = 100 + 100 + 50 + 40 + 5 + 3 or
298 = 200 + 90 + 8.

Problem Solving
Use an open number line to find each sum.

Question 8.
Reasoning José has 181 cards. He collects 132 more cards. How many cards does he have now?

Question 9.
Vocabulary Complete the sentence using two of these terms.
>

Question 10.
Higher Order Thinking Use open number lines to find 446 +215 in two different ways.
446 + 215 = ___

Question 11.
Assessment Practice Mary uses an open number line to find 286 + 137. All of the jumps she draws are greater than 1. Draw what Mary could have done. Write the sum.
286 + 137 = ___

### Lesson 10.3 Add Using Models

Solve & Share

Activity

Use place-value blocks to find 243 + 354. Tell which place value you added first and why. Then draw a picture to show your work.

Visual Learning Bridge

Convince Me!
Are the tens regrouped in the example above? How do you know?

Guided Practice

Use place-value blocks to find each sum. Regroup if needed.

Question 1.
223 + 106 = ___

Question 2.
149 + 362 = ___

Independent Practice
Use and draw blocks to find each sum. Regroup if needed.

Question 3.
151 + 324 = ___

Question 4.
250 + 298 = ___

Question 5.
258 + 109 = ___

Question 6.
187 + 246 = ___

Question 7.
236 + 318 = ___

Question 8.
432 + 365 = ___

Question 9.
Number Sense Jamal says that the sum of 183 + 198 is less than 300. Is Jamal’s answer reasonable? Why or why not?

Problem Solving

Solve the problems below. Show your work.

Question 10.
Reasoning 156 children in a school are girls. 148 children in that school are boys. How many children go to that school?

___ children

Question 11.
Higher Order Thinking Write an addition problem about stickers. Use 3-digit numbers. Then solve the problem.

Question 12.
Assessment Practice which is the sum of 129 +268?

A. 292
B. 294
C. 389
D. 397

### Lesson 10.4 Continue to Add Using Models and Place Value

Activity

Solve & Share

Oak School has 256 students. Pine School has 371 students. How many students do the schools have in all?
Use place-value blocks to help. Draw your blocks below and solve.

Visual Learning Bridge

Convince Me!
Look at the example above. Why don’t the Il tens need to be regrouped to get the final sum?

Guided Practice
Draw blocks to find the partial sums.
Record the partial sums to find the sum.

Question 1.
236 + 252 = ___

Question 2.
328 + 124 = ___

Independent Practice

Question 3.
372 + 281 = ___

Question 4.
429 + 163 = ___

Question 5.
174 + 245 =

Question 6.
Higher Order Thinking Ben said that the sum of 157 and 137 is 284. Nikki said that Ben made a mistake. Who is correct? Explain.

Problem Solving

Solve each problem below. You can use models to help.

Question 7.
Model On Friday, 354 people went to the fair. On Saturday, 551 people went to the fair.
How many people went to the fair in all?
___ people

Question 8.
Higher Order Thinking Write an addition problem in which the partial sum for tens is greater than 10 tens. Draw blocks and show partial sums to solve.
___ + ___ = ___

Question 9.
Assessment Practice Find 448 + 323. Draw place-value blocks and show partial sums to solve.
448 + 323 = ___

### Lesson 10.5 Add Using Place Value and Partial Sums

Activity

Solve & Share
On Monday, 248 people visit the museum. On Tuesday, 325 people visit the museum. How many people visit the museum on Monday and Tuesday? Solve any way you choose. Be prepared to explain your thinking.

Visual Learning Bridge

Convince Me!
Can the problem above be solved by adding the ones first, then the tens, and then the hundreds ? Explain.

Guided Practice
Add. Use partial sums. Show your work. Use place-value blocks if needed.

Question 1.
425 + 148 = ___

Question 2.
394 + 276 = ___

Independent Practice

Question 3.

Question 4.

Question 5.

Question 6.

Question 7.

Question 8.
Higher Order Thinking Mark found the sum of 127 and 345. Explain his mistake. What is the correct sum?

Question 9.
Reasoning Rhea has a $100 bill, four$20 bills, one $10 bill, and three$5 bills. Is this amount greater or less than \$210? Explain.

Problem Solving
Solve each problem. Show your work.

Question 10.
Look for Patterns 349 people are on a boat. 255 people are on another boat. How many people are on both boats?

___ people

Question 11.
163 students are in first grade. 217 students are in second grade. How many students are in both grades?
___ students

Question 12.
Higher Order Thinking Choose a number between 100 and 400. Add 384 to your number. What is the sum? Show your work. Explain the steps you took to find the sum.

Question 13.
Assessment Practice which is the same amount as 238 + 164? Choose all that apply.
200 + 190 + 12
300 + 90 + 12
402
400 + 10 + 2

### Lesson 10.6 Explain Addition Strategies

Activity

Solve & Share

Find 375 + 235. Explain your strategy. Then explain why your strategy works.

Visual Learning Bridge

Convince Me!
Choose a strategy shown above. Explain why it works.

Guided Practice

Use the strategy to solve the problem. Show your work. Then explain your work.

Question 1.
624 + 248 = 872

Independent Practice

Choose any strategy to solve each addition problem. Show your work. Then explain why the strategy works.

Question 2.
212 + 487 = ___

Question 3.
874 + 109 = ___

Question 4.
419 + 532 = ___

Question 5.
650 + 270 = ___

Problem Solving

Solve each problem any way you choose. Show your work.

Question 6.
Reasoning Lee School needs 407 folders for its students. Jefferson School needs 321 folders for its students. How many folders do both schools need?
___ folders

Question 7.
Reasoning There are 229 people at the football game. 108 more people arrive at the game. How many people are at the football game now?
___ people

Question 8.
Higher Order Thinking Tommy found 125 + 598. Since 598 is close to 600, he added 125 + 600 = 725. Then he subtracted 2 to get 723. Why did Tommy subtract 2? Explain.

Question 9.
Assessment Practice There are 192 ants on an ant farm. 397 more ants join the ant farm. How many ants are on the ant farm now? Use the number line to solve. Explain.

### Lesson 10.7 Repeated Reasoning

Problem Solving

Activity

Solve & Share

Solve these problems any way you choose. Explain patterns you see.
63 + 28 = ?
263 + 128 = ?

Thinking Habits
What can I use from one problem to help with another problem? Are there things that repeat?

Visual Learning Bridge

Convince Me!
If you start with 36 and add on 24, in the example above, will you get the same sum? Explain.

Guided Practice
Use repeated reasoning to solve the two problems. Circle the digits that are the same in the sums. Explain why the sums are different.

Question 1.

Independent Practice

Solve each problem.

Question 2.
Write a problem where you need to regroup to make a ten or a hundred. Each addend must be three digits. Draw place-value blocks to solve your problem. Then explain why you needed to regroup.
___ + ___ = ____

Question 3.
Write a problem where you do not need to regroup to make a ten or a hundred. Each addend must be three digits. Draw place value blocks to solve your problem. Then explain why you did not need to regroup.
___ + ___ = ____

Problem Solving

Tickets Sold
The table shows how many tickets were sold at a theater. How many tickets were sold on Thursday and Saturday in all?

Question 4.
Make Sense Which numbers and operation can you use to solve the problem?

Question 5.
Model Write an equation that shows the problem you need to solve.

Question 6.
Generalize Use what you know about adding 3-digit numbers to solve the problem. Explain what you did.

### Topic 10 Fluency Practice

Point&Tally

Find a partner. Get paper and a pencil. Each partner chooses a different color: light blue or dark blue.
Partner I and Partner 2 each point to a black number at the same time. Both partners subtract Partner 2’s number from Partner l’s number.
If the answer is on your color, you get a tally mark. Work until one partner gets seven tally marks.

Topic 10 Vocabulary Review

Understand Vocabulary

Choose a term from the Word List to complete each sentence.

Word List
• break apart
• digits
• hundreds
• mental math
• open number line
• partial sum
• sum

Question 1.
When adding 193 + 564, the sum of 90 + 60 is called a ___

Question 2.
In 709 + 187, 709 is an ___

Question 3.
You can use an ___ to count on.

Question 4.
In 841, there are ___ hundreds

Question 5.
Give the value of each digit in 610.

Question 6.
Use mental math to find 198 + 362.

Use Vocabulary in Writing

Question 7.
Use words to tell how to find 249 + 201. Use terms from the Word List.

### Topic 10 Reteaching

Set A
You can use mental math to add 10 or 100 to 362.

Add using place-value blocks or mental math.

Question 1.
600 + 10 = ___

Question 2.
345 + 100 = ___

Question 3.
543 + 100 = ___

Question 4.
800 + 100 = ___

Question 5.
799 + 10 = ___

Question 6.
119 + 10 = ___

Set B
You can use an open number line to add. Find 327 + 126.
First, place 327 on the line and then count on by 100s, 10s, and 1s.

Use an open number line to find each sum.

Question 7.
594 + 132 = ___

Question 8.
157 + 245 = ___

Set C
You can use or draw place-value blocks and use partial sums to add. Find 276 + 137.

Add. Use partial sums. Show your work. Use drawings of blocks if needed.

Question 9.
408 + 326 = ___

Set D

Thinking Habits
Repeated Reasoning
What can I use from one problem to help with another problem? Are there things that repeat?

Solve each problem. Use partial sums and repeated reasoning. Use drawings of blocks if needed.

Question 10.

Circle the digits that are alike in each sum.

### Topic 10 Assessment Practice

Question 1.
Emily has 100 sun stickers. She has 382 star stickers and 10 moon stickers. How many sun and star stickers does Emily have?

Question 2.
Tyrone collects baseball cards. He gives 138 cards to his friend. Now he has 428 cards. How many cards did Tyrone have before he gave some away?
___ cards

Question 3.
Use the open number line to solve the problem. Write the missing numbers in the boxes.
421 + 250 = ?

Question 4.
Which is the same amount as 528 + 167? Choose all that apply.
500 + 80 + 15
500 + 180 + 15
600 + 90 + 5
600 + 80 + 15

Question 5.
Choose all the equations in which the sum is 488.
478 + 10 = ?
388 + 100 = ?
248 + 240 = ?
200 + 265 = ?

Question 6.
Rich has 335 pennies. Beth has 58 more pennies than Rich. How many pennies do they have in all?
Hundreds

A. 277
B. 393
C. 628
D. 728

Question 7.
Use place value and partial sums to find 472 + 256. Show your work.

472 + 256 = ___

Question 8.
Molly reads 184 pages. Pat reads 294 pages. What is the total number of pages they read in all?
Use any strategy. Show your work and explain.

Question 9.
On Saturday, 449 people visit the zoo. On Sunday, 423 people visit the zoo. How many people visit the zoo in all? Use the open number line to solve. Explain your work.

Recycling Race
Westbrook School is having a recycling contest. The table shows the number of cans each grade collected in February.

Question 1.
How many cans did the first-grade students and the second-grade students collect in all?
Use the open number line to solve.

__ cans

Question 2.
Bruce used partial sums to find how many cans the third-grade students and fourth-grade students collected in all.

Do you agree with his answer?
Circle yes or no.

Question 3.
Which two grades collected a total of 689 cans? Choose any strategy to solve the problem. Show your work. Explain which strategy you used.

The ___ grade and the ___ grade collected a total of 689 cans.