Go through the enVision Math Common Core Grade 2 Answer Key Topic 11 Subtract Within 1,000 Using Models and Strategies and finish your homework or assignments.

## enVision Math Common Core 2nd Grade Answers Key Topic 11 Subtract Within 1,000 Using Models and Strategies

enVision STEM Project: Making Models

Find Out Use a paintbrush as a model of a bee’s leg. Dip the brush in a bowl of sugar. Then dip the brush in a bowl of pepper. Take turns. What happens to the sugar? What happens to the pepper?
Journal: Make a Book Show what you learn in a book. In your book, also:

• Tell how bees help move pollen between plants.
• Show how to use a model to help subtract three-digit numbers.

Review What You Know

Vocabulary

Question 1.
Circle each number that is less than 607.
598
608
706

Explanation:
I circled 598 as it is lessthan 607.

Question 2.
Circle each number that is greater than 299.
352
300
298

Explanation:
I circles 352,300 as they are greater than 299.

Question 3.
Circle the group of numbers that decrease by 100 from left to right.
650, 550, 450, 350
320, 420, 520, 620
570, 560, 550, 540

Explanation:
I circled the first group of numbers 650, 550, 450, 350 as the numbers in this group are in drecreasing order from left to right by 100.

Subtraction Facts

Question 4.
Write each difference.
14 – 7 = ___
11 – 4 = ____
16 – 9 = ___

14 – 7 = 7
11 – 4 = 7
16 – 9 = 7

Explanation:
The differences of all the three questions above is 7, by thinking of the addition facts 7+7=14, 7+4=11, 7+9=16 i wrote the differences.

Partial Differences

Question 5.
Use partial differences to find 54 – 29.

Explanation:
First i parted the number 29 as 20 and 9, then i parted the number 9 as 4 and 5.So, i subtracted easily.

Math Story
Question 6.
Ben has 64 comic books. He gives 36 comic books to friends. How many comic books does Ben have left?
____ comic books

Explanation:
First i parted the number 36 as 30 and 6, then i parted the number 6 as 4 and 2.So, i subtracted easily.

Pick a Project

PROJECT 11A
How tall is the world’s tallest redwood free?
Project: Create a Redwood Trees Booklet

PROJECT 11B
Where does a lot of snow fall?
Project: Build a Snow Sculpture

PROJECT 11C
How high are Florida’s mountains?
Project: Make a Poster About Florida Mountains

Math Modeling

The Chemistry Set

3-ACT MATH PREVIEW

Before watching the video, talk to a classmate: When was the last time you mixed something together? What happened to the items you mixed? How did they change?

### Lesson 11.1 Subtract 10 and 100

Solve & Share

Jill’s Pumpkin Patch sells straw men.
A large straw man costs $134. A medium straw man costs$10 less than a large straw man. A small straw man costs $100 less than a large straw man. What is the cost of a medium straw man? A small straw man? Use dollar bills, place-value blocks, or mental math to solve. Be ready to explain how you solved the problem. Answer: Explanation: A large straw man costs$134, A medium straw man costs $10 less than a large straw man. A small straw man costs$100 less than a large straw man
By using place value blocks i found the value of medium straw man and a small straw man
Cost of medium straw man is $124, cost of small straw man is$34.

Visual Learning Bridge

Convince Me!
Use mental math to find 457 – 10 and 457 – 100. Explain your reasoning.
447 and 357

Explanation:
The number 457 has 4 hundreds 5 tens and 7 ones, if we remove 1 tens from it the answer is 4 hundreds 4 tens and 5 ones that is 447.
The number 457 has 4 hundreds 5 tens and 7 ones, if we remove 1 hundreds from it the answer is 3 hundreds 5 tens and 5 ones that is 357.

Guided Practice
Subtract. Use place-value blocks or mental math. Then write an equation to show the subtraction.

Question 1.

Question 2.

___ – ___ = ___
525 – 10 = 515

Explanation:
In the above questions there are 5 hundreds place value blocks, 2 ten blocks, 5 one blocks and from this 1 ten block is to be subracted.So, if we subtract one ten from it, their will be 4 hundreds, 1 tens and 5 ones that is 515.

Question 3.

___ – ___ = ___
738 – 100 = 638

Explanation:
In the above questions there are 7 hundreds place value blocks, 3 tens blocks, 8 ones blocks and from this 1 hundred block is to be subracted.So, if we subtract one ten from it, their will be 6 hundreds, 3 tens and 8 ones that is 638.

Question 4.

___ – ___= ___
100 – 100 = 0

Explanation:
In the above questions there is 1 hundred block. If we subtract 1 hundred, their will be 0 blocks.So, 100 minus 100 is 0.

Independent Practice

Subtract. Use place-value blocks or mental math.

Question 5.
250 – 10 = ___
250- 10 = 240

Explanation:
The difference between 250 and 10 is 240.

Question 6.
604 – 10 = ___
604 – 10 = 594

Explanation:
The difference between 604 and 10 is 594.

Question 7.
$102 –$100 = ___
102 – 100 = 2

Explanation:
The difference between 102 and 100 is 2.

Question 8.
719 – 10 = ___
719 – 10 = 709

Explanation:
The difference between 719 and 10 is 709.

Question 9.
$400 –$100 = ___
400 – 100 = 300

Explanation:
The difference between 400 and 100 is 300.

Question 10.
308 – 10 = ___

Question 11.
520 – 100 = ___
520 – 100 = 420

Explanation:
The difference between 520 and 100 is 420.

Question 12.
975 – 10 = ___
975 – 10 = 965

Explanation:
The difference between 975 and 10 is 965.

Question 13.
143 – 100 = ___
143 – 100 = 43

Explanation:
The difference between 143 and 100 is 43.

Question 14.
$825 –$10 = ___
$825 –$10 = $815 Explanation: The difference between 825 and 10 is 815. Question 15. 409 – 10 = ___ Answer: 409 – 10 = 399 Explanation: The difference between 409 and 10 is 399. Question 16.$200 – $100 = ___ Answer:$200 – $100 =$100

Explanation:
The difference between 200 and 10 is 100.

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

Question 17.
362 – = 352
362 – 10 = 352

Explanation:
6 tens minus 1 tens is 5tens.So, 362 – 10 = 352.

Question 18.
801 – = 701
801 – 100 = 701

Explanation:
8 hundreds minus 1 hundred is 7 hundreds.So, 801 – 100 = 701.

Question 19.
449 = 549 –
449 = 549 – 100

Explanation:
5 hundreds minus 1 hundred is 4 hundreds.So, 549 – 100 = 449.

Question 20.
657 – = 647
657 – 10 = 647

Explanation:
5 tens minus 1 tens is 4tens.So, 362 – 10 = 352.

Question 21.
215 – = 205
215 – 10 = 205

Explanation:
1 tens minus 1 tens is 0tens.So, 215 – 10 = 205.

Question 22.
700 – = 690
700 – 10 = 690

Explanation:
10 tens minus 1 tens is 9tens.So, 700 – 10 = 690.

Problem Solving

Solve each problem. Show your work.

Question 23.
enVision® STEM Marni is studying facts about bees. She finds that one type of bee can pollinate 955 plants each day. A different type of bee pollinates 100 fewer plants. How many plants does it pollinate?

Explanation:
Marni tells that one Bee can pollinate 995 plants and another Bee caan pollinate 100 fewer than the first Bee.
To find the number of plats the second Bee pollinates, subtract 100 from 955.So, 955 – 100 = 855.
Therefore the second Bee can pollinate 855 plants.

Question 24.
Model Alex has five $100 bills, three$10 bills, and four $1 bills. He buys a pair of shoes for$100. How much money does he have left?
___ plants

Explanation:
Model Alex has five $100 bills, three$10 bills, and four $1 bills that means he has 534.If he buys a pair of shoes for$100, he will have$434(534-100=434) left with him. Question 25. Higher Order Thinking Think of a 3-digit number. Write a story about subtracting 100 from your number. Then complete the equation to show your subtraction. Answer: Explanation: 6 hundreds minus 1 hundred is 5 hundreds.So, 559 – 100 = 559. Question 26. Assessment Practice Which equations are true? Choose all that apply. 303 – 10 = 293 493 – 100 = 393 563 – 10 = 453 309 – 100 = 299 Answer: Explanation: In the above subtraction equations the marked equation are true. ### Lesson 11.2 Subtract on an Open Number Line Solve & Share There are 224 girls and some boys in a parade. There are 471 children in the parade. How many boys are in the parade? Use the open number line to solve the problem. Show your work. Answer: Explanation: Add up from 224, the number you are subtracting.Stop at 471. 100+100+10+10+10+10+1+1+1+1+1+1+1=247. The difference between 471 and 224 is 247. Visual Learning Bridge Convince Me! What is another way you could add up to find 382 – 247? Explain. Answer: Guided Practice Use the open number line to subtract. Question 1. 573 – 459 = ___ Answer: Add up from 459, the number you are subtracting.Stop at 573. 100+10+1+1+1+1 = 114. The difference between 573 and 459 is 114. Question 2. 672 – 547 = ___ Answer: Explanation: Add up from 547, the number you are subtracting.Stop at 672. 100+10+10+1+1+1+1+1=125 The difference between 672 and 547 is 125. Independent Practice Use the open number line to subtract. Question 3. 530 – 318 = Answer: Explanation: Add up from 318, the number you are subtracting.Stop at 530. 100+100+10+1+1=212 The difference between 530 and 318 is 212. Question 4. 735 – 429 = ___ Answer: Explanation: Add up from 429, the number you are subtracting.Stop at 735. 100+100+100+1+1+1+1+1+1+1=306. The difference between 735 and 429 is 306. Question 5. 802 – 688 = Answer: Explanation: Add up from 688, the number you are subtracting.Stop at 802. 100+10+1+1+1+1=114 The difference between 802 and 688 is 114. Question 6. Vocabulary Complete the sentences using each word below once. ones add number You can add up to subtract on an open number line. Start at the ___ you are subtracting ___ up hundreds, tens, and ______ Stop at the number you subtract from. Answer: Problem Solving Solve each problem. Check your work. Question 7. Reasoning Yun has 780 blocks. Marsha has 545 fewer blocks than Yun. How many blocks does Marsha have? ___ blocks Answer: Explanation: Add up from 545, the number you are subtracting.Stop at 780. 100+100+10+10+10+1+1+1+1+1=235 The difference between 780 and 545 is 235. Question 8. Higher Order Thinking Use open number lines to find 463 – 258 in two different ways. 463 – 258 = __ Answer: Explanation: First way: Add up from 258, the number you are subtracting.Stop at 463. 100+100+1+1+1+1+1=205. The difference between 463 and 258 is 205. Second way: Count back from 463,the number from which you have to subtract.Stop at 258. 1+1+1+1+1+100+100=205. The difference between 463 and 258 is Question 9. Assessment Practice Write a math story for 653 – 529. Then solve your story. Answer: Explanation: Add up from 529, the number you are subtracting.Stop at 653. 100+10+10+1+1+1+1=124. The difference between 653 and 529 is 124. ### Lesson 11.3 Subtract Using Models Activity Solve & Share Use place-value blocks to find 482 – 127. Tell which place value you subtracted first and why. Then draw a picture to show your work. Answer: Explanation: Take away 1 hundreds Take away 2 tens Regroup 1 tens as 10 ones, take away 7 ones So, 482 – 127 = 355. Visual Learning Bridge Convince Me! Explain why regrouping works in the problem above. Guided Practice Use and draw blocks to find each difference. Show your work. Question 1. Answer: Take away 1 hundreds Regroup 1 hundreds as 10 tens, take away 4 tens Take away 3 ones So, 326 – 143 = 183. Question 2. 363 – 127 = ___ Answer: Explanation: Take away 1 hundreds Take away 2 tens Regroup 1 tens as 10 ones, take away 7 ones So, 363 – 127 = 236. Question 3. 546 – 271 = ___ Answer: Explanation: Take away 2 hundreds Regroup 1 hundreds as 10 tens, take away 7 tens Take away 1 ones So, 546 – 271 = 275. Independent Practice Use and draw blocks to find each difference. Show your work. Question 4. 314 – 152 = ___ Answer: Explanation: Take away 1 hundreds Regroup 1 hundreds as 10 tens, take away 5 tens Take away 2 ones So, 314 – 152 = 162. Question 5. 653 – 419 = ___ Answer: Explanation: Take away 4 hundreds Take away 1 tens Regroup 1 tens as 10 ones, take away 9 ones So, 653 – 419 = 234. Question 6. 438 – 162 = __ Answer: Explanation: Take away 1 hundreds Regroup 1 hundreds as 10 tens, take away 6 tens Take away 2 ones So, 438 – 162 = 276. Question 7. 662 – 480 = ___ Answer: Explanation: Take away 4 hundreds Regroup 1 hundreds as 10 tens, take away 8 tens Take away 0 ones So, 662 – 480 = 182. Question 8. 999 – 834 = ___ Answer: Explanation: Take away 8 hundreds Take away 3 tens Take away 4 ones So, 999 – 834 = 165. Question 9. 599 – 209 = ___ Answer: Explanation: Take away 2 hundreds Take away 0 tens Take away 9 ones So, 599 – 209 = 390. Question 10. 954 – 738 = ___ Answer: Explanation: Take away 7 hundreds Take away 3 tens Take away 8 ones So, 954 – 738 = 216. Question 11. Number Sense Tyler says that the difference of 676 – 367 is greater than 200. Is what Tyler says reasonable? Why or why not? Answer: Yes, the diference of 676-367 is Explanation: Take away 3 hundreds Take away 6 tens Regroup 1 tens as 10 ones, take away 7 ones So, 676 – 367 = 309. Problem Solving Solve each problem below. Show your work. Question 12. Tia collected cans to raise money for school. She collected 569 cans on Monday. Tia collected some more cans on Tuesday. Now she has 789 cans. How many cans did Tia collect on Tuesday? Answer: Explanation: Take away 5 hundreds Take away 6 tens Take away 9 ones So, 789 – 569 = 220. Question 13. Make Sense Josh has these bills. How much money does he have? Answer: Question 14. Higher Order Thinking Write a subtraction problem about recycling. Use 3-digit numbers. Then solve the problem. Answer: Explanation: Take away 3 hundreds Regroup 1 hundreds as 10 tens, take away 5 tens Take away 2 ones So, 314 – 152 = 162. Question 15. Assessment Practice Use the place value-blocks to find 864 – 319. Which is the difference? A. 454 B. 535 C. 545 D. 555 Answer: Explanation: Take away 3 hundreds Take away 1 tens Regroup 1 tens as 10 ones, take away 9 ones So, 864 – 319 = 545. ### Lesson 11.4 Subtract Using Models and Place Value Activity Solve & Share Larissa has$353. She buys a pair of basketball shoes for $117. How much money does she have left over? Use or draw place-value blocks to solve. Be ready to explain what you did and why it works. Answer: Explanation:$117 + $117 =$234.
Subtract 2 hundreds
Subtract 3 tens
First subtract 3 ones
Regroup 1 tens as 10 ones. then subtract 1 ones
So, $353 –$234 = \$119.

Visual Learning Bridge

Convince Me!
Find 254 – 174. Jason says he can subtract 100, and then 4, and then 70 to find the difference. Do you agree? Explain.

Explanation:
Subtract 1 hundreds
First subtract 4 tens
Regroup 1 hundreds as 10 tens. then subtract 3 tens
Subtract 4 ones
So, 254 – 174 = 80.

Guided Practice
Draw blocks to find the partial differences. Record the partial differences to find the difference.

Question 1.

Independent Practice

Draw blocks to find the partial differences. Record the partial differences to find the difference.

Question 2.
598 – 319 = __

Explanation:
Subtract 3 hundreds
Subtract 1 tens
First subtract 8 ones
Regroup 1 tens as 10 ones. then subtract 1 ones
So, 598 – 319 = 279.

Question 3.
794 – 452 = ___

Explanation:
Subtract 4 hundreds
Subtract 5 tens
Subtract 2 ones
So, 7+4 – 452 = 342

Question 4.
871 – 355 = ___

Explanation:
Subtract 3 hundreds
Subtract 5 tens
First subtract 1 ones
Regroup 1 tens as 10 ones. then subtract 4 ones
So, 871 – 355 = 516.

Solve. Draw blocks to help.

Question 5.
Higher Order Thinking There were 642 people at the beach. There were 271 adults at the beach. The rest were children. How many children were at the beach?

___ children

Explanation:
Subtract 2 hundreds
First subtract 4 tens
Regroup 1 hundreds as 10 tens. then subtract 3 tens
Subtract 1 ones
So, 642 – 271 = 371.

Problem Solving

Solve each problem. You can use models to help. Show your work.

Question 6.
Model Jeff has 517 baseball cards. He has 263 football cards. How many more baseball cards than football cards does he have?
___ more baseball cards

Explanation:
Subtract 2 hundreds
First subtract 1 tens
Regroup 1 hundreds as 10 tens. then subtract 5 tens
Subtract 3 ones
So, 517 – 263 = 254.

Question 7.
Reasoning Felipe has 453 stamps in his collection. Emily has 762 stamps in her collection. How many more stamps does Emily have?

___ more stamps

Explanation:
Subtract 4 hundreds
Subtract 5 tens
First subtract 2 ones
Regroup 1 tens as 10 ones. then subtract 1 ones
So, 762 – 453 = 309.

Question 8.
Assessment Practice Which numbers complete this partial difference problem for 423 – 219? Choose all that apply.

Explanation:
Subtract 2 hundreds
Subtract 1 tens
First subtract 3 ones
Regroup 1 tens as 10 ones. then subtract 6 ones
So, 423 – 219 = 204.

### Lesson 11.5 Explain Subtraction Strategies

Activity

Solve & Share

Find 532 – 215. Use any strategy. Then explain why your strategy works.

Visual Learning Bridge

Convince Me!
Show how to count up on the open number line to find 437 – 245. Explain why your way works.

Explanation:
I counted up from 245 to 437.
I started at 245, I added 192, i ended at 437.So, 245+192=437.
Therefore, 437-245= 192.

Guided Practice
Subtract any way you choose. Show your work. Then explain why the strategy works.

Question 1.

Subtract 1 hundreds
Subtract 1 tens
First subtract 5 ones
Regroup 1 tens as 10 ones. then subtract 1 ones
So, 345-116=229.

Independent Practice

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

Question 2.
312 – 179 = __

Explanation:
Subtract 1 hundreds
Regroup 1 hundreds as 10 tens, subtract 7 tens
First subtract 2 ones
Regroup 1 tens as 10 ones. then subtract 7 ones
So, 312 – 179 =133.

Question 3.
464 – 155 = ___

Explanation:
Subtract 1 hundreds
Subtract 5 tens
First subtract 5 ones
Regroup 1 tens as 10 ones. then subtract 1 ones
So, 464-155=309.

Question 4.
612 – 478 = ___

Explanation:
Subtract 2 hundreds
Regroup 1 hundreds as 10 tens, subtract 7 tens
First subtract 2 ones
Regroup 1 tens as 10 ones. then subtract 6 ones
So, 612-478=134.

Question 5.
Number Sense Use place value to find 748 – 319. Complete the equations.
319 = 300 + ___ + 9
Hundreds: 748 – __ = ___
Tens: ___ – 10 = __
Ones: ___ – __ = ___
319 = 300 + 10 + 9
Hundreds: 748 – 300 = 448
Tens: 30 – 10 = 20
Ones: 18 – 9 = 9

Explanation:
Subtract 3 hundreds
Subtract 1 tens
First subtract 8 ones
Regroup 1 tens as 10 ones. then subtract 1 ones
So, 748-319=428

Problem Solving

Solve each problem. Show your work.

Question 6.
Explain Ava wants to use mental math to find 352 – 149. Show how she could find the difference. Is this a good strategy for Ava to use? Explain why or why not.

Question 7.
Higher Order Thinking Kristin found 562 – 399 = 163 using an open number line. She added up to subtract. First she added 1, then 100, and then 62.
Draw Kristin’s number line. Do you think Kristin’s strategy was helpful? Explain.

Explanation:
I counted up from 399 to 562.
I started at 399, I added 163, i ended at 562.So, 399+163=562.
Therefore, 562-399=163.

Question 8.
Assessment Practice Jeff counted back on this open number line to find 812 – 125.
Use the numbers on the cards to find the missing numbers in the open number line. Write the missing numbers.

Explanation:
Count back from 692, 5 lessthan 692 is 687
Count forward  from 692, 10 morethan 692 is 702
10 morethan 702 is 712
100 morethan 712 is 812.

### Lesson 11.6 Persevere

Solve & Share

Jody wants to bake 350 muffins. She bakes one batch of 160 muffins and one batch of 145 muffins. How many more muffins does Jody need to bake?
Solve any way you choose. Show your work. Be prepared to explain why your way works.

Thinking Habits
What do I know? What do I need to find? How can I check that my solution makes sense?
Jody wants to bake 350 muffins. She bakes one batch of 160 muffins and one batch of 145 muffins
I know the total number of muffins baked 160+145=305
I need to find the number of muffins to be baked
350-305=45.
I checked my answer by drawing place value blocks.

Visual Learning Bridge

Convince Me!
What questions can you ask yourself when you get stuck? Be ready to explain how questions can help.

Guided Practice
Solve the problem. Remember to ask yourself questions to help. Show your work.

Question 1.
Kim had 455 shells. First, she gives 134 of the shells to a friend. Then she finds 54 more shells. How many shells does Kim have now?

Kim will have 375 shells.

Explanation:
Kim had 455 shells. First, she gives 134 of the shells to a friend
455-134=?
Count up to subtract
134+66=200
200+255=455
455-134=6+60+255=321

Then she finds 54 more shells
321+54=?
321+4=325
325+50=375

The number of shells kim have now is Kim have now 321+54=375.

Independent Practice

Use the table to solve each problem. Show your work.

Question 2.
How much heavier is a grizzly bear than an arctic wolf and a black bear together?
544 pounds

Explanation:
Arctic wolf and black bear together weigh
176+270=446

Grizzly bear weigh 990pounds, subtract weight of arctic wolf and a black bear together from it.
990-446=?
Count up to subtract
446+54=500
500+490=990
990-446=54+490=544
Therefore a Grizzly bear weighs 544pounds more than arctic wolf and a black bear together.

Question 3.
How much less does a black bear weigh than the weight of 2 mule deer?
126 pounds

Explanation:
Weight of mule deer is 198 pounds
Weight of 2 mule deers is 396

Weight of black bear is 270

396-270=?
Count up to subtract
270+30=300
300+96=396
396-270=30+96=126
Therefore the black bear is 126pounds lessthan weight of 2 mule deers.

Question 4.
How much more does a polar bear weigh than an arctic wolf, a black bear, and a mule deer together?

301 pounds

Explanation:
Weight of polar bear is 945
Weight of an arctic wolf, a black bear, and a mule deer together is 176+270+198=644
176+270=
176+200=376
376+24+46=446
446+198=
446+100=546
546+54+44=644

Subrtact 945 and 644
945-644=?
Count up to subtract
644+56=700
700+200=900
900+45=945
945-644=56+200+45=301
Therefore a polarbear weighs 301pounds morethan the weight of an arctic wolf, a black bear, and a mule deer together.

Problem Solving

Big Truck
The picture at the right shows the height of a truck and the height of a smokestack on top of the truck. The height of a bridge is 144 inches. Use the information at the right. Can the truck travel under the bridge?

Question 5.
Make Sense What do you know? What are you trying to find?
I know
Height of the bridge is 144inches
I am trying to find the height of the truck.

Question 6.
Make Sense What hidden question do you need to answer first? Find the answer to the hidden question.
I need to answer the hidden question that is the toatal height of the truck.

Explanation:
The height of the truck is 112+27=?inches
112+7=119
119+20=139inches

Question 7.
Explain Can the truck travel under the bridge? Show your work. Why does your solution make sense?
Yes, the truck can travel under the bridge.

Explanation:
The height of the truck is 112+27=?inches
112+7=119
119+20=139inches
Height of the bridge is 144inches
As the height of the truck is lessthan the height of the bridge the truck can travel under the bridge.

### Topic 11 Vocabulary Review

Understand Vocabulary
Draw a line from each term to its example.
Word List
• difference
• hundreds
• mental math
• open number line
• partial differences
• regroup

Explanation:
I matched the words with the example given.

Question 4.
This open number line is incomplete. It needs to show counting back to find 538 – 115. Write in the missing numbers and labels.

Explanation:
The misssing numbers are 115, 118, 158 and 358
The labels are open number line, hundreds and difference.

Use Vocabulary in Writing

Question 5.
Find 235 – 127. Use terms from the Word List to explain your work.

Explanation:
I used open number line to find the difference between 235 and 127,
The difference is 108.

### Topic 11 Reteaching

Set A

You can subtract 10 or 100 mentally.

Subtract using place-value blocks or mental math.

Question 1.
426 – 10 = __

Explanation:
Ten minus 426 is 416.

Question 2.
345 – 100 = ___

Explanation:
Hundred minus 345 is 245.

Question 3.
287 – 100 = ___

Explanation:
Hundred minus 287 is 187.

Question 4.
309 – 10 = ___

Explanation:
Ten minus 309 is 299.

Question 5.
800 – 10 = ___

Explanation:
Ten minus 800 is 790.

Question 6.
140 – 100 = __

Explanation:
Hundred minus 140 is 40.

Set B
Find 213 – 108.
One Way
Start at 108 on an open number line. Add up to 213.

Count back from 213 of an open number line.

So, 213 – 108 = 105

Use the open number line to subtract.

Question 7.
449 – 217 = ___

Explanation:
I counted up from 217 to 449 to find the difference 449-217.
449-217=232.

Question 8.
903 – 678 = ___

Explanation:
I counted up from 678 to 903 to find the difference 903-678.
903-678=225.

Set C
You can draw place-value blocks to show subtraction. Find 327 – 219.

Subtract 2 hundreds
Subtract 1 tens
First subrtact 7 ones
Regroup 1 tens as 10 ones, subtract 2 ones
327-219=108.

Draw blocks to find the partial differences. Record the partial differences to find the difference.

Question 9.
653 – 427 = ___

Explanation:
I subrtacted 4 hundreds 2 tens and 7 ones.
653-427=226.

Set D
Thinking Habits
Persevere
What do I know?
What do I need to find?
How can I check that my solution makes sense?

I knew how many peenies Marni have, how many she gave to her sister and how many pennies she got from her mother.
I need to find the number of pennies Marni will have after she gets pennies from her mother.
I can check my solution by drawing place value blocks to subtract.

Solve the problem. Ask yourself questions to help.

Question 10.
Marni has 354 pennies. First, she gives 149 pennies to her sister. Then, she gets 210 more pennies from her mother. How many pennies does Marni have now?
415 pennies

Explanation:
Marni has 354 pennies. First, she gives 149 pennies to her sister
354-149=?
149+1=150
150+204=354
354-149=1+204=205

she gets 210 more pennies from her mother
205+210=?
205+10=215
215+200=415
Therefore, there are 415pennies with Marni now.

### Topic 11 Assessment Practice

Question 1.
Which equals 100 less than 763? Choose all that apply.
663
600 + 60 + 3
863
800 + 60 + 3
600 + 100 + 60

Explanation:
100 minus 763 is 663, it can also be written as 600+60+3.

Question 2.
The open number line below shows subtraction.

Complete the equation. Write the numbers being subtracted and the difference.
___ – ___ = ___
587 – 464 = 123

Explanation:
The numbers being subtracted are 100, 10, 10, 1, 1, 1.
100+10+10+1+1+1=123
Therefore, 587-464=123.

Question 3.
Nico collected 235 coins. Amber collected 120 fewer coins than Nico. How many coins did they collect in all?
A. 350
B. 115
C. 500
D. 550
A.350

Explanation:
Nico collected 235 coins
Amber collected 120 fewer coins than Nico
Number of coins Nico collected 235-120=?
120+15=135
135+100=235
235-120=15+100=115.

235+115=?
235+15=250
250+100=350.
Therefore, they collected 350coins in altogether.

Question 4.
There are 537 boys and 438 girls at the concert. How many more boys than girls are at the concert?
A. 89
B. 99
C. 101
D. 109
B.99

Explanation:
There are 537 boys and 438 girls at the concert
537-438=?
438+12=450
450+87=537
537-438=12+87=99
Therefore, there are 99 boys more than girls in the concert.

Question 5.
Show how to add up on an open number line to find 740 – 490. Then write the difference below.

740 – 490 = ___

Question 6.
Look at your work in Item 5. Explain how you used the number line to find the difference.
I added up from 490 to 740, the difference between 740 and 490 is 250.

Question 7.
Use place value and partial differences to find 374 – 157. Show your work.
374 – 157 = ___

Explanation:
Subtract 1 hundred
Subtract 15 tens
First subtract 4 ones
Regroup 1 tens as 10 ones, then subtract 3 ones
So, 374-157=217.

Question 8.
Draw place-value blocks to find the difference of 643 – 418.

643 – 418 = ___

Explanation:
The difference between 643 and 418 is 225.

The chart shows the number of beads sold at Betty’s craft store for 4 weeks.

Question 1.
How many more beads did Betty sell in Week 2 than in Week 1? Write the missing numbers in the equation. Then use any strategy to solve.
__ – ___ = ___
536 – 400 = 136

Explanation:
536-400=136
So, Betty sold 136 beads more in week2 than in week1.

Question 2.
458 glass beads were sold in Week 3. The other beads sold in Week 3 were plastic. How many plastic beads were sold in Week 3?
Use the open number line to solve.

___ – __ = ___
Explain how you solved the problem. Tell how you know your answer is correct.
675 – 458 = 217.

Explanation:
I used open number line to solve this problem, i counted and added up from 458 to 675.
So, the difference between 675 and 458 is 217.We can check the answer by counting back from 675 to 458.

Question 3.
Dex buys 243 beads at Betty’s store. He uses 118 of them to make a bracelet. How many beads does Dex have left?
Solve the problem. Show your work. Explain which strategy you used.

___ – ___ = ___

243 – 118 = 125

Explanation:
I used open number line to solve this problem, i counted and added up from 118 to 243.
So, the difference between 243 and 118 is 125.

Question 4.
Part A
What is the hidden question in the problem?
The hidden question is the sum of blue, orange and white beads.
Part B
Solve the problem. Show your work. Explain which strategy you used.