NS 2.2*1%7
Round two-place
decimals to one decimal or the nearest whole
&&66
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UNDERLYING SKILLS AND CONCEPTS:
number and judge the reasonableness of the rounded answer.
rounding
Round Two-Place Decimals
3
1. If the digit in the tenths
place is less than 5,
drop the decimal part of the
number.
1
?
round 3.?
down to 3.
If less than 5,
2. If the digit in the tenths
place is 5 or more, round up
to the next whole number.
E x am p l E
.
round 3.?
up to 4.
If 5 or greater than 5,
Round to
Jody bought a charm for her bracelet for
$7.95.
What was the cost of the charm
to the nearest dollar?
Check
Ones
7
.
Tenths
Hundredths
9
5
A place value chart can help you round.
The number in the tenths place is 9.
So, round up: $7.95 rounds to $8.
E x am p l E
9 is greater
than 5.
(9 # 5)
Round 7.95
up to 8.
2
Tickets to the dance sold for $4.85 each.
The total amount of money spent for tickets was $378.30.
The school paper said that over 100 students went to dance.
Use rounding to determine whether the paper was correct.
$4.85 rounds to $5. $5 ! 100 " $500
Since $500 is a lot more than $378, the paper was not correct.
page 134
Chapter 12 – Lesson 1
D – © CSL Associates, Inc. All rights reserved.
a
K
ey Ide
To round a decimal to Round to
Check
the nearest whole
number, look at the
digit in the tenths
Ones
Tenths
place.
Name
P RAC T I C E
Round each decimal to the nearest whole number.
1. 4.84
5
2. 2.62
3
3. 0.45
0
4. 24.18
24
5. 10.02
10
6. 0.38
0
7. 0.73
1
8. 10.22
10
9. 49.50
50
10. 0.79
1
11. 9.50
10
7
12. 6.99
13. Judy picked up the following items 14. Glenda has $12.45 saved.
at the store:
She wants to buy a sweater
a box of pencils for $1.89,
that costs $19.99.
a pen for $3.95, and
Is it reasonable for her to think she
a marker for $0.89.
can buy the sweater
She has $7. Use rounding to
if she saves $5.74 more?
determine whether she has enough
No, she would only have
money to buy all of the items.
Yes, she has enough money.
about $18.
D – © CSL Associates, Inc. All rights reserved.
Use rounding to help choose the best answer for each question.
15. Jasmine jogged 2.75 miles each day
for a week. About how
many miles total did she jog?
A 5.5 miles
B 10 miles
C 21 miles
D 42 miles
Math
Reasoning
16. Joseph bought a bag of oranges for
$3.85. He handed the clerk
a 10-dollar bill. About how much
change should he get back?
A $2
B $4
C $6
D $10
Number Sense
MR 2.1
17. Cindy said that 4 CDs at $11.85 each were going to cost her $60.80.
Is her answer reasonable? Explain how you can tell.
No, her answer is not reasonable. If you round $11.85 to the
nearest dollar, and multiply you get 4 $12 or $48.
Chapter 12 – Lesson 1
page 135
MCX94.HW.CL.G4.FM&Lesson.v211
8/2/04
19:16
Page 90
Name
…at home!
P RAC T I C E
Round each decimal to the nearest whole number.
1. 5.97
6
2. 2.82
3
3. 0.37
0
4. 48.19
48
5. 11.03
11
6. 0.21
0
7. 0.67
1
8. 12.02
12
9. 38.50
39
10. 0.86
1
11. 9.65
10
12. 6.51
7
13. Robin picked up the following
14. Ellen has $15.75 saved.
items at the store:
She wants to buy sandals that cost
a box of pencils for $1.89,
$19.99.
a pen for $3.95, and
Is it reasonable for her to think she
paper for $1.69.
can buy the sandals if she saves
She has $7. Use rounding to
$4.95 more?
determine whether she has enough
Yes, she would have about
money to buy all of the items.
No, she would need about $8
$21.
to buy all the items.
15. Margo jogged 1.75 miles each day
for a week. About how
many miles total did she jog?
A 5.5 miles
B 14 miles
C 21 miles
D 42 miles
Math
Reasoning
16. Robert bought a bag of potatoes for
$2.59. He handed the clerk
a 10-dollar bill. About how much
change should he get back?
A $3
B $5
C $7
D $9
Number Sense
MR 2.1
17. Maria said that 3 CDs at $11.85 each were going to cost her $48.95.
Is her answer reasonable? Explain how you can tell.
No, her answer is not reasonable. If you round $11.85 to the
nearest dollar, and multiply you get 3 $12 or $36.
page 90
Home Resource and Homework
Chapter 12 Lesson 1
D – © CSL Associates, Inc. All rights reserved.
Use rounding to help choose the best answer for each question.
MCX94TEG4Ch01_32.v8.5.2 2/26/01 19:01 Page 249
Name
P RAC T I C E
Round each decimal to the nearest whole number.
1. 4.84
5
2. 2.62
3
3. 0.45
0
4. 24.18
24
5. 10.02
10
6. 0.38
0
7. 0.73
1
8. 10.22
10
9. 49.50
50
10. 0.79
1
11. 9.50
10
7
12. 6.99
13. Judy picked up the following items 14. Glenda has $12.45 saved.
at the store:
She wants to buy a sweater
a box of pencils for $1.89,
that costs $19.99.
a pen for $3.95, and
Is it reasonable for her to think she
a marker for $0.89.
can buy the sweater
She has $7. Use rounding to
if she saves $5.74 more?
determine whether she has enough
No, she would only have
money to buy all of the items.
Yes, she has enough money.
about $18.
D – © CSL Associates, Inc. All rights reserved.
Use rounding to help choose the best answer for each question.
15. Jasmine jogged 2.75 miles each day
for a week. About how
many miles total did she jog?
A 5.5 miles
B 10 miles
C 21 miles
D 42 miles
Math
Reasoning
16. Joseph bought a bag of oranges for
$3.85. He handed the clerk
a 10-dollar bill. About how much
change should he get back?
A $2
B $4
C $6
D $10
Number Sense
MR 2.1
17. Cindy said that 4 CDs at $11.85 each were going to cost her $60.80.
Is her answer reasonable? Explain how you can tell.
No, her answer is not reasonable. If you round $11.85 to the
nearest dollar, and multiply you get 4 $12 or $48.
Chapter 12 – Lesson 1
Student Book Page
page 135
Name
…at home!
P RAC T I C E
Round each decimal to the nearest whole number.
1. 5.97
6
2. 2.82
3
3. 0.37
0
4. 48.19
48
5. 11.03
11
6. 0.21
0
7. 0.67
1
8. 12.02
12
9. 38.50
39
10. 0.86
1
11. 9.65
10
12. 6.51
7
13. Robin picked up the following
14. Ellen has $15.75 saved.
items at the store:
She wants to buy sandals that cost
a box of pencils for $1.89,
$19.99.
a pen for $3.95, and
Is it reasonable for her to think she
paper for $1.69.
can buy the sandals if she saves
She has $7. Use rounding to
$4.95 more?
determine whether she has enough
Yes, she would have about
money to buy all of the items.
No, she would need about $8
$21.
to buy all the items.
15. Margo jogged 1.75 miles each day
for a week. About how
many miles total did she jog?
A 5.5 miles
B 14 miles
C 21 miles
D 42 miles
Math
Reasoning
16. Robert bought a bag of potatoes for
$2.59. He handed the clerk
a 10-dollar bill. About how much
change should he get back?
A $3
B $5
C $7
D $9
Number Sense
MR 2.1
17. Maria said that 3 CDs at $11.85 each were going to cost her $48.95.
Is her answer reasonable? Explain how you can tell.
No, her answer is not reasonable. If you round $11.85 to the
nearest dollar, and multiply you get 3 $12 or $36.
page 90
Home Resource and Homework
Chapter 12 Lesson 1
D – © CSL Associates, Inc. All rights reserved.
Use rounding to help choose the best answer for each question.