This document provides information and examples about percents. It discusses writing percents as fractions or decimals, writing fractions and decimals as percents, translating and solving percent sentences, and solving problems involving percents. Examples are provided for converting between percents, fractions, and decimals. Percent sentences are explained and examples given for finding a percent of a whole number and what percent one number is of another.

1. Percents
1. Write a percent as a fraction or decimal number.
2. Write a fraction or decimal number as a percent.
3. Translate and solve percent sentences.
4. Solve problems involving percents.

2. Review
d
c
b
a
=
Ratio: A comparison of two quantities using a quotient (fraction).
Proportion: Two ratios set equal.
Cross Products: Cross products are equal.
Percent:
20% = 20 out of 100
0
20
10
=
1
or 0.2
5
=
A ratio representing some part out of 100.
bc
ad =

3. Percents to Decimals
55%
Drop % and move decimal point 2 places to the left.
=.55
38% =.38
14.5% =.145
.25% =.0025
%
2
1
45 %
.5
45
= 455
.
=

4. Percents to Fractions
55%
Change to a decimal, then Read It, Write It, Reduce It
=.55
38% =.38
14.5% =.145
.25% =.0025
%
2
1
45 %
.5
45
= 455
.
=
100
55
=
20
11
=
100
38
=
50
19
=
1000
145
=
200
29
=
10000
25
=
400
1
=
1000
455
=
200
91
=
Tenths
Hundredths
Thousandths
Ten
Thousandths
0 . 1 2 3 4

5. Decimals to Percents
Move the decimal point 2 places to the right and add %.
= 55%
.55
= 38%
.38
= 250%
2.5
= .3%
.003

6. Fractions to Percents
Change to a decimal and then to a percent.
4
3
75
.
= %
75
=
8
5
625
.
= %
.5
62
=
5
2
3 4
3.
= %
340
=

7. Slide 1- 7
Copyright © 2011 Pearson Education, Inc.
What is 7/8 as a percent?
a) 78%
b) 87%
c) 87.5%
d) 718%
3.2

8. Slide 1- 8
Copyright © 2011 Pearson Education, Inc.
What is 7/8 as a percent?
a) 78%
b) 87%
c) 87.5%
d) 718%
3.2

9. Percent Sentences
A percent of a whole is a part of the whole.
% multiply total
(follows “of”)
part
=
36% of 72 is what number?
.36 ∙ 72 = x
.36 (72) = x
25.92 = x
36% of 72 is 25.92.

10. Percent Sentences
A percent of a whole is a part of the whole.
% multiply total part
=
.42 ∙ x = 31.92
.42 x = 31.92
x = 76
42% of what number is 31.92?
42% of 76 is 31.92.

11. Percent Sentences
x ∙ 63 = 56
63 x = 56
x = .8888888…
88.9% of 63 is 56.
What percent of 63 is 56?
x = 88.9%

12. Slide 1- 12
Copyright © 2011 Pearson Education, Inc.
2.4% of 130 is what number?
a) 31.2
b) 3.12
c) 1.83
d) 0.18
3.2

13. Slide 1- 13
Copyright © 2011 Pearson Education, Inc.
2.4% of 130 is what number?
a) 31.2
b) 3.12
c) 1.83
d) 0.18
3.2

14. Slide 1- 14
Copyright © 2011 Pearson Education, Inc.
What percent of 48 is 51.84?
a) 93%
b) 98%
c) 108%
d) 109%
3.2

15. Slide 1- 15
Copyright © 2011 Pearson Education, Inc.
What percent of 48 is 51.84?
a) 93%
b) 98%
c) 108%
d) 109%
3.2