Name
1.5
?
Number and
Operations—5.2.C
MATHEMATICAL PROCESSES
5.1.A, 5.1.E
Round Decimals
Essential Question
How can you use place value to round decimals to
a given place?
Unlock
Unlock the
the Problem
Problem
The Gold Frog of South America is one of the smallest
frogs in the world. It is 0.386 of an inch long. What is this
length rounded to the nearest hundredth of an inch?
• Underline the length of the Gold Frog.
• Is the frog’s length about the same
as the length or the width of a large
paper clip?
One Way Use a place-value chart.
• Write the number in a place-value chart and circle the
digit in the place value to which you want to round.
• In the place-value chart, underline the digit to the
right of the place to which you are rounding.
• If the digit to the right is less than 5, the digit in the
place value to which you are rounding stays the same.
If the digit to the right is 5 or greater, the digit in the
rounding place increases by 1.
Ones
0
• Drop the digits after the place to which you are rounding.
•
Tenths
Hundredths
Thousandths
3
8
6
Think: Does the digit in the rounding
place stay the same or increase by 1?
So, to the nearest hundredth of an inch, a Gold Frog is
© Houghton Mifflin Harcourt Publishing Company • Image Credits: (tr) © Purestock/Alamy Images
about __ of an inch long.
Another Way Use place value.
The Little Grass Frog is the smallest frog in North America.
It is 0.437 of an inch long.
A What is the length of the frog to the nearest
hundredth of an inch?
0.437
↓
0.44
7>5
B What is the length of the frog to the nearest
tenth of an inch?
0.437
↓
0.4
3<5
So, to the nearest hundredth of an inch, the frog is
So, to the nearest tenth of an inch, the frog is about
about __ of an inch long.
__ of an inch long.
Module 1
29
Share
Share and
and Show
Show
Write the place value of the underlined digit. Round each
number to the place of the underlined digit.
1. 0.673
2. 4.282
___
___
3. 12.917
___
___
___
___
Name the place value to which each number was rounded.
4. 0.982 to 0.98
5. 3.695 to 4
___
6. 7.486 to 7.5
___
___
Problem
Problem Solving
Solving
Write the place value of the underlined digit. Round each
number to the place of the underlined digit.
7. 0.592
8. 6.518
___
___
9. 0.809
___
___
___
___
Round 16.748 to the place named.
__
11. hundredths
__
13.
Write Math
Explain why any number less than 12.5 and greater
than or equal to 11.5 would round to 12 when rounded to the nearest
whole number.
14.
Write Math
nearest tenth.
30
12. ones
__
Explain what happens when you round 4.999 to the
© Houghton Mifflin Harcourt Publishing Company
10. tenths
Name
Problem
Problem Solving
Solving
Insect Speeds (meters per second)
Use the table for 15–18.
15. The speeds of two insects when rounded
to the nearest whole number are the same.
Which two insects are they?
Insect
Speed
Dragonfly
6.974
Horsefly
3.934
Bumblebee
2.861
Honeybee
2.548
Housefly
1.967
16. What is the speed of the housefly rounded to
the nearest hundredth?
17. The speed of an insect is about 3.9 meters per
© Houghton Mifflin Harcourt Publishing Company • Image Credits: (tr) ©Don Farrall/Getty Images
second. Which insect could it be?
18.
What’s the Error? Mark said
that the speed of a dragonfly rounded to the
nearest tenth was 6.9 meters per second. Is he
correct? If not, what is his error?
19.
Multi-Step A rounded number for the speed
of an insect is 5.67 meters per second. What are the fastest
and slowest speeds to the thousandths that could round to
5.67? Explain.
Write Math
Show Your Work
Module 1 • Lesson 5 31
Mathematical Processes
M
Model ¥ Reason ¥ Communicate
M
Daily
Daily Assessment
Assessment Task
Task
Fill in the bubble completely to show your answer.
20. Chef Round uses 1.257 kilograms of meat for his famous meatballs.
There are four packages at the market. Which amount is closest to
1.257 kilograms?
A
1.26 kg
B
1.2 kg
C
1.3 kg
D
1.35 kg
21. Representations The table shows the neck lengths for four giraffes in
the Long-Necked Friends Sanctuary. Which two giraffes have necks that
are the same length when rounded to the nearest tenth?
A
Spot and Stretch
Giraffe’s Name
B
Mittens and Spot
Mittens
5.632
C
Mittens and Stretch
Spot
5.725
Stretch
5.405
D
Spot and Zippy
Zippy
5.657
Neck Length (feet)
22. Multi-Step Janis sells friendship bracelets at a fair. She has three
A
16.5 cm, 16.76 cm, 16.6 cm
B
16.6 cm, 16.7 cm, 16.5 cm
C
16.5 cm, 16.8 cm, 16.6 cm
D
16.3 cm, 16.5 cm, 16.5 cm
TEXAS Test Prep
23. To which place value is the number rounded?
6.706 to 6.71
32
A
ones
C
hundredths
B
tenths
D
thousandths
© Houghton Mifflin Harcourt Publishing Company
bracelets that are 16.53 cm, 16.755 cm, and 16.55 cm long. She
wants to label the lengths to the nearest tenth of a centimeter.
In order, how should she label the bracelets?
Number and Operations—5.2.C
MATHEMATICAL PROCESSES 5.1.A, 5.1.E
H o mewo rk
and Practice
1.5
Name
Round Decimals
Write the place value of the underlined digit. Round each
number to the place of the underlined digit.
1.
0.782
2.
4.071
3.
21.939
4.
8.155
5.
34.09
6.
4.276
Round 8.293 to the place named.
7. hundredths _
8. tenths _
9. ones _
Round 12.462 to the place named.
10. tenths _
11. hundredths _
12. ones _
Problem
Problem Solving
Solving
13. What is Anita’s speed rounded to the
nearest hundredth?
© Houghton Mifflin Harcourt Publishing Company
14. The speeds of two runners when rounded to the
nearest tenth are the same. Which two runners
are they?
Runner Speeds (meters per second)
Runner
Speed
Luke
0.178
Margola
0.169
Anita
0.277
Shateel
0.289
Module 1 • Lesson 5
33
TEXAS Test Prep
Lesson
Lesson Check
Check
Fill in the bubble completely to show your answer.
15. To which place value is the number rounded?
16. To which place value is the number rounded?
8.293 to 8.29
0.799 to 0.8
A
ones
A
ones
B
tenths
B
tenths
C
hundredths
C
hundredths
D
thousandths
D
thousandths
17. Which number is 5.389 rounded to the nearest
18. Which number is 7.323 rounded to the nearest
hundredth?
tenth?
A
5.4
A
7.3
B
5.38
B
7.4
C
5.39
C
7.32
D
5.399
D
7.33
19. A baker uses 2.327 kilograms of blueberries for muffins. There are four
packages at the fruit market. Which amount is closest to 2.327 kilograms?
2.3 kg
B
2.42 kg
C
2.33 kg
D
2.4 kg
20. Multi-Step The chart shows the length of each
student’s pencil. Which person has a pencil
length that can be rounded up to the nearest
tenth of an inch?
34
A
Lori
B
Ping
C
Jason
D
Annie
Student
Pencil Length (inches)
Lori
6.61
Ping
5.055
Jason
4.91
Annie
6.5
© Houghton Mifflin Harcourt Publishing Company
A