Finding the Percent of a Number Name 13-5

Name
Practice
13-5
Finding the Percent of a
Number
Find the percent of each number.
1. 42% of 800
2. 5.6% of 425
3. 85% of 15
4. 33_13% of 678
5. 12% of 65
6. 58% of 324
7. 98% of 422
8. 32% of 813.5
9. 78% of 219
10. 13% of 104
11. 24% of 529
12. 4.5% of 82
13. 64% of 912
14. 128% of 256
15. 63% of 1,368
17. Estimation Estimate 68% of 32, then find an
exact number. Which is greater?
For 18 and 19, round your answer to the nearest whole number.
18. An adult has 206 bones. Of those, 2.9% are found in the inner ear.
How many bones in the human body are found in the inner ear?
19. About 12.6% of the bones are vertebrae in the human back. How
many bones in the human body are vertebrae?
20. 45 is 12% of which number?
A 540
B 450
C 375
D 5.4
21. Writing to Explain Without calculating, tell which is greater, 52%
of 3,400 or 98% of 1,500. Explain.
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Enrichment
Practice 13-5
13-5
16. About 42% of the flag of the United States is red.
On a flag that is 9 feet tall and 15 feet wide, how
many square feet is red?
54
Topic 13
Name
Practice
13-5
Finding the Percent of a
Number
Find the percent of each number.
1. 42% of 800
4. 33_13% of 678
7. 98% of 422
10. 13% of 104
13. 64% of 912
2.
336
5.
226
413.56 8.
13.52 11.
583.68 14.
5.6% of 425
12% of 65
32% of 813.5
24% of 529
128% of 256
23.8 3.
6.
7.8
260.32 9.
126.9612.
327.6815.
17. Estimation Estimate 68% of 32, then find an
exact number. Which is greater?
58% of 324
78% of 219
4.5% of 82
63% of 1,368
12.75
187.92
170.82
3.69
861.84
56.7 sq ft
Estimate: 21:
exact: 21.76 exact
answer is greater
For 18 and 19, round your answer to the nearest whole number.
18. An adult has 206 bones. Of those, 2.9% are found in the inner ear.
How many bones in the human body are found in the inner ear?
6
19. About 12.6% of the bones are vertebrae in the human back. How
many bones in the human body are vertebrae?
26
20. 45 is 12% of which number?
A 540
B 450
C 375
D 5.4
21. Writing to Explain Without calculating, tell which is greater, 52%
of 3,400 or 98% of 1,500. Explain.
52% of 3,400 is greater. About half of 3,400 is
greater than about all of 1,500.
54
Topic 13
© Pearson Education, Inc. 6
Enrichment
Practice 13-5
13-5
16. About 42% of the flag of the United States is red.
On a flag that is 9 feet tall and 15 feet wide, how
many square feet is red?
85% of 15
Name
Reteaching
13-5
Finding the Percent of a
Number
Find 77% of 240.
First estimate.
77% ⬇ 75% ⫽ _34
3 ⫻ 240 ⫽ 180
_
4
Use a proportion.
Use a decimal.
Change the percent to a decimal.
77% ⫽ 0.77
Multiply.
0.77 ⫻ 240 ⫽ 184.8
Write the percent as a fraction.
77
77% ⫽ ___
100
Write the proportion and solve.
77
x ⫽ ___
___
100
240
100x ⫽ 18,480
18,480
100x ⫽ _____
____
100
100
The answer 184.8 is close to the estimate 180.
x ⫽ 184.8
Find the percent of each number.
2. 50% of 72
3. 72% of 88
4. 18% of 97
5. 66% of 843
6. 46% of 388
7. 89% of 111
8. 0.7% of 392
9. 110% of 640
Reteaching 13-5
1. 25% of 24
10. Geometry Ava’s aquarium is 10 in. tall, 15 in. long, and 8 in. wide.
The aquarium is 95% filled with water. How many cubic inches of
water are in the aquarium?
11. DeWayne used his music club membership card to get 15% off the
cost of a CD. If the regular price of the CD was $15.95, how much
did DeWayne pay?
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12. Marla bought a dress for $89.99. She paid 6.5% sales tax. What
was the total cost of the dress?
13. Writing to Explain Tell how you could use a proportion to find
138% of 967. Why is the solution greater than the original number?
Topic 13
53
Name
Reteaching
13-5
Finding the Percent of a
Number
Find 77% of 240.
First estimate.
77% ⬇ 75% ⫽ _34
3 ⫻ 240 ⫽ 180
_
4
Use a proportion.
Use a decimal.
Change the percent to a decimal.
77% ⫽ 0.77
Multiply.
0.77 ⫻ 240 ⫽ 184.8
Write the percent as a fraction.
77
77% ⫽ ___
100
Write the proportion and solve.
77
x ⫽ ___
___
100
240
100x ⫽ 18,480
18,480
100x ⫽ _____
____
100
100
The answer 184.8 is close to the estimate 180.
x ⫽ 184.8
Find the percent of each number.
4. 18% of 97
7. 89% of 111
6
17.46
98.79
2. 50% of 72
5. 66% of 843
8. 0.7% of 392
3.
36
556.38 6.
2.744 9.
72% of 88
46% of 388
110% of 640
63.36
178.48
704
10. Geometry Ava’s aquarium is 10 in. tall, 15 in. long, and 8 in. wide.
The aquarium is 95% filled with water. How many cubic inches of
water are in the aquarium?
1,140 in.3
11. DeWayne used his music club membership card to get 15% off the
cost of a CD. If the regular price of the CD was $15.95, how much
did DeWayne pay?
$13.56
12. Marla bought a dress for $89.99. She paid 6.5% sales tax. What
was the total cost of the dress?
© Pearson Education, Inc. 6
$95.84
I would use
a proportion:
___
___
138
x
967 ⴝ 100 . Then, I would cross-multiply: 100x ⴝ 133,446.
Then I can divide both sides by 100 to find the number:
x ⴝ 1334.46. The solution is greater than the original
number because the percent is greater than 100. Topic 13 53
13. Writing to Explain Tell how you could use a proportion to find
138% of 967. Why is the solution greater than the original number?
Reteaching 13-5
1. 25% of 24