1. 3.2 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 A ratio representing some part out of 100. Percent:
A comparison of two quantities using a quotient (fraction).
Proportion:
Two ratios set equal.
Cross Products:
Cross products are equal.
A ratio representing some part out of 100.
Percent:
20% = 20 out of 100

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

4. 55% =.55 Percents to Fractions
Change to a decimal, then Read It, Write It, Reduce It
Tenths
Hundredths
Thousandths
Ten Thousandths . 1 2 3 4
55%
=.55
38%
=.38
14.5%
=.145
.25%
=.0025

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

6. Fractions to Percents
Change to a decimal and then to a percent.

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

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

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

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

11. Percent Sentences What percent of 63 is 56? x 56 ∙ 63 = 63 x = 56

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

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

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

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

16. Percent Sentences
On Monday, January 17, 2012, the Morning Sentinel reported it planned to cut 100 full-time jobs in a bid to return to profitability. This is 6% of the newspaper’s workforce. How many employees does the Sentinel have?
Percent ∙ whole = part
Percent:
6% = .06
Whole: x
.06 x = 100
Part:
100
x =
x = 1667
Sentinel has 1,667 employees.

17. Percent Sentences
Jamal purchases a new surfboard that costs $570. The sales tax is 7%, what is the total cost of the surfboard?
Percent ∙ whole = part
Percent:
7% = .07
Whole:
570
.07(570) = x
Part: x
x = 39.90
What did we find?
Sales tax.
Total cost = cost plus tax.
Total cost is $