4.1
Round to the Nearest Ten
or Hundred
?
Essential Question How can you round numbers?
Texas Essential
Knowledge and Skills
Number and Operation—3.4.B
Round to the nearest 10 or 100 or use compatible numbers to
estimate solutions to addition and subtraction problems
How can you round
numbers?
Also 3.2.C
MATHEMATICAL PROCESSES
3.1.C Select tools, technology, and techniques
3.1.D Communicate mathematical ideas and reasoning
Are You Ready?
Access Prior Knowledge
Use the Are You Ready? 4.1 in the
Assessment Guide to assess students’
understanding of the prerequisite skills
for this lesson.
Vocabulary
Lesson Opener
Making Connections
Go to Multimedia eGlossary at
thinkcentral.com
Review with students what they have learned about whole numbers and place value.
What are the names of the places in a 3-digit number? (ones, tens, hundreds)
Using the Digital Lesson
Why do you think Doc said rounding will help you get a better idea of how high the
biplane is? (It is easier to picture 400 feet than 376 feet.)
Learning Task
Connect the story to the problem.
• What information is given to you in this problem? (the number of feet a biplane rose
above the ground)
Resources
• How high above the ground was the biplane? (376 feet)
• How can you write 376 in expanded form? (300 + 70 + 6)
• What is the value of each digit in 376? (3 hundreds, 7 tens, 6 ones)
Literacy and Mathematics
You may choose one or more of the following activities.
• Have each student draw a number line that has a range from 0 to 400. Have them
draw the point that shows 376.
• Have students research the story of the first flight and the Wright brothers. Have
them write a short paragraph about what they learned and the importance of this
event in history.
For the student
For the teacher
Interactive
Student Edition
provides students
with an interactive learning
environment!
Digital Management
Center organizes program
resources by TEKS!
eTeacher
Edition
Math on the Spot
Video Tutor
Online Assessment
System
iTools Virtual
Manipulatives
Soar to Success Math
Online Intervention
Lesson 4.1 101A
Name
4.1
Unlock the Problem
?
When would you round a number?
Discuss the problem. Be sure that students
understand that 32 is an exact number and they
need to round 32 to the nearest ten.
Essential Question
Mia’s baseball bat is 32 inches long. What is its
length rounded to the nearest ten inches?
One Way
This method uses place value to round numbers to
the closest ten or hundred. Read and discuss with
students the rules for place value to round a number.
Think: The digit in the ones place tells if
the number is closer to 30 or 40.
●
2 < 5
↑
So, the length of Mia’s bat rounded to the nearest
30 inches.
ten inches is _
B Round 457 to the nearest hundred.
place that I am rounding. If the digit is less than 5, the
digit in the rounding place stays the same. If the digit is
5 or greater, the digit in the rounding place increases by
1. I write zeros for the digits to the right of the rounding
place.
English Language Learners
32
Write zero as the ones digit.
• How is rounding to the nearest ten and rounding
to the nearest hundred using place value the
same? In each case, I look at the digit to the right of the
Think: The digit in the tens place tells if
the number is closer to 400 or 500.
●
5 = 5
457
↑
So, the hundreds digit increases by one.
Write 5 as the hundreds digit.
Write zeros as the tens and ones digits.
© Houghton Mifflin Harcourt Publishing Company
• Will you increase the hundreds digit by 1 or will it
stay the same? Increase by 1
Remember
When you round a number,
you find a number that
tells you about how much
or about how many.
So, the tens digit stays the same. Write 3 as the
tens digit.
The digit 2 is less than 5, so the digit in the rounding place
stays the same. 32 is closer to 30 than to 40.
• What is the digit to the right? 5
Use place value to round.
A Round 32 to the nearest ten.
• When rounding 32 to the nearest ten why do you
compare the digit to the right of the rounding
place to 5? It tells you if you have to change the digit.
• What digit do you want to round? 4
How can you round numbers?
Unlock
Unlock the
the Problem
Problem
One Way
For Example B, discuss with students the rules for
rounding using place value. Have students round 457
to the nearest hundred.
Number and
Operations—3.4.B
Also 3.2.C
MATHEMATICAL PROCESSES
3.1.A, 3.1.C
Round to the Nearest Ten
or Hundred
• Find the place to which you want
to round.
• Look at the digit to the right.
• If the digit is less than 5, the digit
in the rounding place stays the same.
• If the digit is 5 or greater, the digit
in the rounding place increases by one.
• Write zeros for the digits to the
right of the rounding place.
500 .
So, 457 rounded to the nearest hundred is _
ELL Language Support
Module 4 101
Verbal / Linguistic
Small Group
Leveled Activities
ELPS
Beginning: Activity 37
2.D.1, 2.I.3, 2.I.5
Intermediate: Activity 22
1.A.1, 3.G.1, 4.C.1
Strategy: Describe
Advanced: Activity 47
2.D.2, 2.I.5, 3.D.1
Advanced High: Activity 29
3.E, 4.F.10, 4.G.4
Materials: two classroom objects (such as a stapler and an eraser), Number Line
(see eTeacher Resources), color pencils
thinkcentral.com for the ELL Activity
Guide containing these leveled activities.
101 Module 4
ELPS 2.C.3, 2.I.3, 3.G.1
• Students gain understanding of rounding using a number line by
describing objects that are closer.
• Review the meaning of closer by placing one classroom object close to
the group and the other object far away from the group. Which object
is closer? Have students explain how they decided which object was
closer.
• Display a number line labeled from 0 to 100, in increments of 10. Circle
the number 20 in blue and the number 30 in red. Mark a point at 27. Is
27 closer to 20 or to 30? 30 How can you tell? Possible answer: the distance
from 27 to 30 is shorter than the distance from 27 to 20.
Hands
On
Another Way
Use a number line to round.
Locate and label 718 on the number lines.
A Round 718 to the nearest ten.
718
700
710
Another Way
B Round 718 to the nearest hundred.
Discuss with students that there are different ways
to round a number. Remind students that previously
they learned how to round to the nearest 10 and 100
using number lines. Then, have students complete
Parts A and B.
718
720
700
750
800
720 than it is
718 is closer to _
700 than it is
718 is closer to _
710 .
to _
800 .
to _
720 .
So, 718 rounds to _
700 .
So, 718 rounds to _
Hands
On
• Between which two tens is 718? Which ten is it
closer to? Explain. 710 and 720; 718 is closer to 720. It
is only two numbers away from 720 but 8 numbers away
from 710.
Math Talk
Share
Share and
and Show
Show
What is the greatest
number that rounds to
50 when rounded to
the nearest ten? What
is the least number?
Explain.
Locate and label 46 on the number line.
Round to the nearest ten. Check students’ work.
46
30
40
• How is rounding a 3-digit number, like 718, to the
nearest ten similar to rounding the number to the
nearest hundred? Possible answer: in each case, I find
Mathematical Processes
50
the two tens or hundreds the number is between and then
I decide which is closer.
60
1.
40 .
50 than it is to _
46 is closer to _
2.
50 .
46 rounded to the nearest ten is _
Round to the nearest ten.
• How is rounding a 3-digit number to the nearest
ten different than rounding to the nearest
hundred? Possible answers: the number lines I use are
greatest 54; least 45; Possible
explanation: since this group of
numbers rounds to 50 (45, 46, 47, 48, 49,
50, 51, 52, 53, 54), the greatest number
is 54 and the least number is 45.
different. To round to the nearest ten, I need to find the
two tens that the number is between. To round to the
nearest hundred, I need to find the two hundreds that the
number is between. I write a zero for the digit in the ones
place when rounding to ten. I write a zero for the digits in
the tens and ones places when rounding to hundred.
Round to the nearest hundred.
50
3. 51 _
4.
500
463 _
5.
580
576 _
600
_
6.
300
298 _
7.
300
_
840
844 _
800
_
102
© Houghton Mifflin Harcourt Publishing Company
Round to the nearest ten and hundred.
• Explain how using place value is similar to using a
number line? Possible explanation: when you use place
value, you look to the right of the rounding place to see
which ten or hundred the digit is closer to. If the next digit
is 5 or greater, it will be closer to the next ten or hundred.
When you use a number line, you can see which ten or
hundred the number is closer to.
Share and Show
Enrich
Visual
Individual / Partners
• Write this riddle on the board:
I am a number between 440 and 460. When rounded to the nearest
ten, I am 450. When rounded to the nearest hundred, I am 400. My
ones digit is an even number, but it is not 8. What number am I? 446
• Have students use the first clue to list the numbers between 440 and
460. Then have students use the remaining clues to eliminate numbers
until there is only one number left. Encourage students to check their
work to make sure their answer satisfies all the clues.
• Challenge students to make up their own riddles involving rounding
3-digit numbers. Have them exchange their riddles with a partner and
solve.
Go to Go to thinkcentral.com for additional enrichment
activities in the Enrich Activity Guide.
The first problem connects to one of the learning
models. Use the checked exercises for Quick Check.
Students should show their answers for the Quick
Check on the MathBoard.
3
2
Quick Check
1
IF
THEN
a student misses the checked exercises
Differentiate Instruction with
RtI Tier 1 Lesson 22
Math Talk
Mathematical Processes
Use Math Talk to focus on student’s understanding
of rounding. Encourage students to explain their
thinking.
Lesson 4.1
102
Name
Problem
Problem Solving
Solving
Problem Solving
Use the table for 8–11.
In Problems 8–11 students use information from a
table and rounding to the nearest ten or hundred to
solve problems. Problem 11, encourages students to
discuss strategies they can use to determine which
numbers round to 800.
8.
Visitors to the Giraffe
Exhibit
On which day did about 900 visitors
come to the giraffe exhibit?
Day
Sunday
9.
Problems
To the nearest ten, how many visitors
came to the giraffe exhibit on Sunday?
890 visitors
Problems 12 and 13 require students to use higher
order thinking skills. You may wish to encourage
students to use a number line to find the numbers.
10.
To the nearest hundred, how many
visitors came to the giraffe exhibit
on Tuesday ?
Go Deeper
Number of Visitors
Sunday
894
Monday
793
Tuesday
438
Wednesday
362
Thursday
839
Friday
725
Saturday
598
400 visitors
To extend their thinking, ask students to find the
greatest number that rounds by hundreds to 500.
11.
Write Math
Multi-Step On which two days
did about 800 visitors come to the
giraffe exhibit?
Show Your Work
Monday and Thursday
COMMON ERRORS
C
Example To round 438 to the nearest hundred,
students may look at the 8 and round to 500.
Springboard to Learning Have students circle the
place to which they are rounding and underline the
number to the immediate right before rounding.
M
Math
on the Spot
Video Tutor
V
Through the Math on the Spot Video Tutor,
students will be guided through an interactive
solving of this type of H.O.T. problem. Use this
video to also help students solve the H.O.T.
problem in the Interactive Student Edition. With
these videos and the H.O.T. problems, students
will build skills needed in the TEXAS assessment.
12.
© Houghton Mifflin Harcourt Publishing Company • Image Credits: ©Peter Barritt/Alamy Images
E
Error
Students may round numbers incorrectly
because they do not look at the place to the
immediate right.
Write five numbers that
round to 360 when rounded to the
nearest ten.
Possible answer: 356, 357, 359, 361, 364
13.
What’s the Error? Cole
said that 555 rounded to the nearest
ten is 600. What is Cole’s error?
Explain.
The answer should be 560. Possible
explanation: Cole rounded to the nearest
hundred instead of the nearest ten.
Module 4 • Lesson 1 103
3
RtI Tier 1 Lesson 22
2
1
Enrich 16
Name
Name
Math on the Spot videos are in the
Interactive Student Edition and at
thinkcentral.com.
3.4.B
OBJECTIVE Round 2- and 3-digit numbers to the nearest ten or hundred.
Round and About
Round the distances to the nearest hundred and ten.
When you round a number, you find a number that tells you
about how much or about how many.
Nearest Hundred
1.
628 miles
600
miles
630
miles
Step 1 Look at the digit to the right
of the tens place.
2.
704 miles
700
miles
700
miles
3.
58 miles
100
miles
60
miles
76
• If the ones digit is 5 or greater,
the tens digit increases by one.
ones place
• If the ones digit is less than 5,
the tens digit stays the same.
6> 5
The digit in the ones place is 6.
4.
So, the digit 7 in the tens place
increases to 8.
hundred, you need to look at the tens place. Since
Think: To round to the nearest hundred, look at the tens
digit. 2 is less than 5, so the hundreds digit stays the
same. So, 128 rounded to the nearest hundred is 100.
128
5 5 5, the digit in the hundreds place, 0, increases by
tens place
one, making it 100.
5.
Round to the nearest ten.
Explain why 58 can be rounded to the nearest
hundred even though there is not a digit in the hundreds place.
Possible explanation: when you round to the nearest
So, 76 rounded to the nearest ten is 80.
© Houghton Mifflin Harcourt Publishing Company
Nearest Ten
Use place value to round 76 to the nearest ten.
Step 2 Write zero for the ones digit.
103 Module 4
Enrich 16
1
Round to the Nearest Ten or Hundred
LESSON
22
Stretch Your Thinking Write a number that is the same when
rounded to the nearest hundred and ten. Explain.
1. 24
20
2. 15
20
3. 47
50
Possible explanation: 203; to round 203 to the nearest
4. 42
40
5. 81
80
6. 65
70
hundred, you look at the tens digit, which is 0.
0 , 5, so 203 rounds to 200. To round 203 to the
Round to the nearest hundred.
7. 176
200
8. 395
400
9. 431
400
10. 421
400
11. 692
700
12. 470
500
Number and Operations
nearest ten, you look at the ones digit, which is 3.
3 , 5, so 203 rounds to 200.
43
Enrich
© Houghton Mifflin Harcourt Publishing Company
E16
Mathematical Processes
Model ¥ Reason ¥ Communicate
Daily
Daily Assessment
Assessment Task
Task
3
Fill in the bubble for the correct answer choice.
14.
15.
A fountain shoots water 460 feet into the air.
Which shows 460 rounded to the nearest hundred?
A
450
B
400
C
470
D
500
B
328
249
D
360
NO
•
YES
70
C
80
B
50
D
90
TEXAS Test Prep Coach
Test Prep Coach helps teachers to identify common
errors that students can make.
In the Test Prep exercise, if students selected:
A They rounded to the hundred instead of the
nearest ten.
C or D They rounded to the wrong ten.
440
C
450
D
430
© Houghton Mifflin Harcourt Publishing Company
Use Tools What is 438 rounded to the nearest ten?
B
Enrich 16
Homework and Practice
Lesson 4.1
A
400
•
•
Multi-Step A train has four cars. There are 29 people in
the first car and 39 people in the second car. There are
33 people in the third car and 42 people in the fourth car.
Which is closest to the total number of people in the
second and third car?
A
Soar to Success Math
Warm-Up 15.15, 15.17
TEXAS Test Prep
17.
1
THEN
IF
380
C
2
Can students round numbers to the nearest ten
and hundred?
Use Tools Which number rounds to 300 when rounded
to the nearest hundred?
A
16.
Daily Assessment Task
104
?
Essential Question
Write
Math
How can you round numbers? I can use a place value or
a number line.
Differentiated Centers Kit
Literature
Soccer Bash
Students read the book and
use place value to determine if
there’s enough money for the
soccer team’s party.
Activities
Block It Out!
Students complete blue Activity
Card 1 by representing numbers
with base-ten blocks.
Lesson 4.1
104
5
Number and Operations—3.4.B
Also 3.2.C
MATHEMATICAL PROCESSES 3.1.A, 3.1.C
Ho mewo rk
and Practice
4.1
Fill in the bubble completely to show your answer.
12.
739
600
700
800
1.
700
800 .
739 is between _
and _
2.
700
800 .
739 is closer to _
than it is to _
900
Round to the nearest ten and hundred.
5.
220
215 _
6.
770
767 _
200
_
600
_
200
198 _
8.
800
_
550
547 _
9.
850
852 _
15.
500
_
200
_
900
_
Problem
Problem Solving
Solving
© Houghton Mifflin Harcourt Publishing Company
10.
A team sweatshirt costs $38. What
is this cost rounded to the nearest
ten dollars?
11.
There are 372 workers at a software
company. What is this number
rounded to the nearest hundred?
$40
400
Module 4 • Lesson 1
Homework and Practice
Use the Homework and Practice pages to provide
students with more practice on the concepts and
skills of this lesson.
105-106
Module 4
Which number rounds to 500 when
rounded to the nearest hundred?
A
345
A
552
B
334
B
548
C
335
C
446
D
346
D
560
105
106
Hot Lunches Sold at
Brown School
Which is the number of hot lunches
sold on Monday rounded to the
nearest ten?
Number of Hot
Lunches Sold
Day
Monday
448
A
400
Tuesday
402
B
450
Wednesday
382
C
500
Thursday
393
Friday
476
D
7.
13.
Use the table for 14–16.
14.
700 .
3. 739 rounded to the nearest hundred is _
640
636 _
Which number rounds to 340 when
rounded to the nearest ten?
440
Multi-Step Which is closest to the
total number of hot lunches sold on
Thursday and Friday?
A
400
B
800
C
500
D
900
16.
Multi-Step Which is closest
to the difference of the number
of hot lunches sold on Monday
and Tuesday?
A
50
B
60
C
100
D
40
© Houghton Mifflin Harcourt Publishing Company
Round to the Nearest Ten or Hundred
Locate and label 739 on the number line.
Round to the nearest hundred.
4.
TEXAS Test Prep
Lesson
Lesson Check
Check
Name