Addition and subtraction are opposite operations, or inverse operations. So you can use addition to check subtraction.
Math Talk Mathematical Processes
Explain how you know your answers are reasonable.
Module 5
145
Share Share and and Show Show Math Talk
Estimate. Then use place value to find 627 – 384. Add to check your answer.
1.
Mathematical Processes
Did you need to regroup to find the difference? Explain.
Estimate. __ – __ = __
627 – 384 __
+ 384 __
Since __ is close to the estimate of __ , the answer is reasonable. Estimate. Then find the difference. Estimate: _
2.
3.
Estimate: _
386 – 123 __
4.
519 –205 __
Estimate: _
5.
642 –159 __
Estimate: _
242 –220 __ Math Talk Mathematical Processes
Which exercises can you compute mentally? Explain why.
Problem Problem Solving Solving Algebra Find the unknown number.
86 – _ 62
10.
146
7.
372
8.
– __ 240
The Dessert Store bought 120 peaches. The bakers made peach jam and peach pies with 98 of the peaches. How many peaches are left to make peach cobbler?
537 – __ 169
11.
9.
629 – __ 335
Multi-Step The stamp store has 857 stamps for sale. They sold 156 stamps on Monday and 348 stamps on Tuesday. How many stamps do they have left for sale on Wednesday?
Sense or Nonsense? Nina says to check subtraction, add the difference to the number you started with. Does this statement make sense? Justify.
15.
Use Math Language Do you have to regroup to find 523 – 141? Explain. Then solve.
Number of Tickets
Show Your Work
Module 5 • Lesson 2
147
Mathematical Processes M Model ¥ Reason ¥ Communicate M
Daily Daily Assessment Assessment Task Task Fill in the bubble for the correct answer choice. You may add to check your answer. 16.
17.
18.
A company has 228 large water bikes and 136 small water bikes. How many more large water bikes does the company have than small water bikes? A
92
C
112
B
94
D
191
A store has 448 blankets and 607 pillows. How many fewer blankets does the store have than pillows? A
168
C
161
B
159
D
249
Multi-Step Hannah, Sam, and Alex play a game. Hannah has 325 points. Sam has 234 points. Alex has 124 fewer points than Hannah and Sam together. How many points does Alex have? A
683
C
435
B
559
D
201
TEXAS Test Prep
148
There are 842 seats in the school auditorium. 138 seats need repairs. How many seats do not need repairs? A
Fiona subtracts 617 – 234 = 483. Is her answer correct? Explain.
Module 5 • Lesson 2
149
TEXAS Test Prep
Lesson Lesson Check Check
11.
13.
150
There are 526 students at the New City Elementary School. Of these, 178 are in the third grade. How many students are not in the third grade?
10.
In the morning, there are 472 visitors at the Street Fair. In the afternoon there are 218 visitors. About how many more visit the fair in the morning?
A
448
A
about 250
B
348
B
about 350
C
358
C
about 700
D
458
D
about 500
The third grade collects 417 bottles to recycle. The fourth grade collects 378 bottles. How many more bottles does the third grade collect?
12.
A museum store has 239 posters, 125 calendars, and 547 books. How many more books than posters does the museum store have?
A
49
A
114
B
139
B
312
C
39
C
422
D
149
D
308
Multi-Step Darius has 127 photos. Miquel has 179 photos and Jillian has 467 photos. How many more photos does Jillian have than both Darius and Miquel?
14.
Multi-Step Beth, Dan, and Yoshi collect stamps. Beth has 157 stamps. Dan has 265 stamps. Yoshi has 79 fewer stamps than Beth and Dan. How many stamps does Yoshi have?