Name
5.1
?
Number and
Operations—3.4.B
MATHEMATICAL PROCESSES
3.1.A, 3.1.G
Estimate Differences
Essential Question
How can you use compatible numbers and rounding
to estimate differences?
Unlock
Unlock the
the Problem
Problem
The largest yellowfin tuna caught weighed
427 pounds. The largest grouper caught
weighed 436 pounds. About how much
more did the grouper weigh than the
yellowfin tuna?
You can estimate to find about how
much more.
One Way
• Does the question ask for an exact
answer? How do you know?
• Circle the numbers you need to use.
Yellowfin tuna
Use compatible numbers.
© Houghton Mifflin Harcourt Publishing Company • Image Cr edits: (b) ©PhotoLink/Photodisc/Getty Images; (t) ©Bill Curtsinger/Getty Images
Think: Compatible numbers are numbers that are
easy to compute mentally and are close to
the real numbers.
436 → 435
– 4 2 7 → __
–425
__
So, the grouper weighed about
_ pounds more than the yellowfin tuna.
Another Way
A
B
Grouper
Use place value to round.
761 → 8 0 0
– 528 → __
–
__
642 →
–__
287 → –__
300
Think: Round both numbers to
the same place value.
Math Talk
Mathematical Processes
Explain a different way
you can round each
number in Example B
to find another
estimate.
Module 5
139
Share
Share and
and Show
Show
Use compatible numbers to
estimate the difference.
1.
546 →
550
−209
_→ −
__
Math Talk
Mathematical Processes
Explain another way
you can estimate
546 – 209.
Use rounding or compatible numbers to estimate
the difference.
2.
57
− 21
_
5.
3.
−
6.
429 − 51
−
4.
642
− 137 −
__
374
− 252 −
__
491 − 270
=
−
=
7.
Explain how you would estimate 301 – 281. Tell why you
chose that method.
8.
Visitor records showed that there were 632 students at
the marina last week. There were 396 girls. About how
many students were boys? Explain.
140
© Houghton Mifflin Harcourt Publishing Company
Problem
Problem Solving
Solving
Name
Problem
Problem Solving
Solving
Use the table for 9–13.
© Houghton Mifflin Harcourt Publishing Company
9.
Largest Saltwater
Fish Caught
Type of Fish
About how many more pounds does
the Pacific halibut weigh than the yellowfin
tuna? Explain.
10.
Communicate Melissa said the weight of the Yellowfin
Tuna was about 500 pounds. Is Melissa’s answer correct?
11.
What’s the Question? The answer is about 800 pounds.
12.
Sean said the three fish together weigh about
1,300 pounds. Justify why you agree or disagree.
13.
Multi-Step About how much more is the
total weight of the Pacific halibut and conger than the
weight of the yellowfin tuna? Explain.
Weight in Pounds
Pacific
Halibut
533
Conger
350
Yellowfin
Tuna
427
Module 5 • Lesson 1
141
Mathematical Processes
M
Model ¥ Reason ¥ Communicate
M
Daily
Daily Assessment
Assessment Task
Task
Fill in the bubble for the correct answer choice.
14.
15.
16.
There are 157 geocaches in my town. There are
921 geocaches in Naveen’s city. About how many
more geocaches are hidden in Naveen’s city than
in my town?
A
650
C
850
B
750
D
950
The Duke family is on vacation. They travel 432 miles
on Monday. They travel 279 miles on Tuesday. About
how many fewer miles does the Duke family travel on
Tuesday than on Monday?
A
200 miles
C
150 miles
B
300 miles
D
50 miles
Multi-Step There are 246 girls and 229 boys at the zoo.
After lunch, 164 of the children go home. About how
many children are still at the zoo after lunch?
A
320
C
640
B
480
D
90
TEXAS Test Prep
142
A total of 926 people went to a fishing tournament.
Of these people, 607 arrived before noon. Which is
the best estimate of the number of people who arrived
in the afternoon?
A
150
B
500
C
300
D
250
© Houghton Mifflin Harcourt Publishing Company
17.
Number and Operations—3.4.B
MATHEMATICAL PROCESSES 3.1.A, 3.1.G
H o mewo rk
and Practice
5.1
Name
Estimate Differences
Use rounding or compatible numbers to estimate
the difference.
1.
96
–_
22
2.
−
__
532
–_
175
3.
−
__
753
–_
227
−
__
Use the table for 4–6.
4.
5.
About how many more
students like soccer than
kickball?
About how many more
students like kickball than
softball?
Survey of Favorite Sport
Sport
Students
Kickball
383
Soccer
528
Softball
166
6.
The number of boys that like soccer is
316. About how many girls like soccer?
8.
A total of 683 hot dogs and
hamburgers were sold at the softball
game. If 278 were hot dogs, about how
many hamburgers were sold at the
game?
Problem
Problem Solving
Solving
© Houghton Mifflin Harcourt Publishing Company
7.
A total of 843 people went to watch the
soccer match. If 519 were students,
about how many people at the match
were adults?
Module 5 • Lesson 1
143
TEXAS Test Prep
Lesson
Lesson Check
Check
Fill in the bubble completely to show your answer.
11.
13.
144
Manuel scores 789 points playing a
video game. Jackie scores 416 points.
About how many more points did
Manuel score than Jackie?
A
300
B
500
C
400
D
200
The Middletown School Library has
638 history books and 289 art books.
About how many more history
books does the library have than
art books?
A
300
B
200
C
400
D
500
Multi-Step A museum has 324 oil
paintings, 227 watercolors, and
158 statues. Which is the best
estimate of how many more oil and
watercolor paintings there are than
statues?
10.
12.
14.
On a trip, Mr. Peters flies 868 miles.
Then he flies another 331 miles.
About how many more miles did
Mr. Peters fly on the first part of
his trip?
A
450 miles
B
350 miles
C
650 miles
D
550 miles
In a nature reserve, a scientist
counted 927 frogs and 328 toads.
About how many more frogs than
toads were counted by the scientist?
A
500
B
700
C
600
D
400
Multi-Step There are 262 students
in the 2nd grade and 298 students
in the 3rd grade. If 227 students take
the bus to school, which is the best
estimate of how many students do
not take the bus?
A
100
A
325
B
400
B
600
C
200
C
425
D
300
D
550
© Houghton Mifflin Harcourt Publishing Company
9.