Section Section Section Section Section 32.ppt
- 1. Percents 3.2 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
- 16. Percent Sentences .06 x = 100 x = 1666.66666 Sentinel has 1,667 employees. Percent ∙ whole = part x = 1667 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: 6% = .06 Whole: x Part: 100
- 17. Percent Sentences .07(570) = x x = 39.90 Total cost is $609.90. Percent ∙ whole = part What did we find? Jamal purchases a new surfboard that costs $570. The sales tax is 7%, what is the total cost of the surfboard? Percent: 7% = .07 Whole: 570 Part: x Sales tax. Total cost = cost plus tax. 90 39 00 570 . . 90 609.