Fractions, Decimals and Percents

1. Fractions, Decimals and Percents

2. Pre-Skill Check Write each phrase as a decimal in numerical form. 0.67 4.5 201.53 0.379 8.04 Sixty-seven hundredths Four and five tenths Two hundred one and fifty-three hundredths Three hundred seventy-nine thousandths Eight and four hundredths

3. 0.25 = 2.3 = 70.609 = 3.05 = 2.007 = 271.092 = Any number to the left of the decimal is a whole number. The number to the right of the decimal is the numerator of the fraction. The place value of the LAST digit in the number is the denominator. 25 100 3 2 10 609 70 1000 5 3 100 7 2 1000 92 271 1000 Decimals to fractions Ones . Tenths Hundredths 75 Ex: 4.75 = 4 75 4 100

4. = 0.7 = 0.22 = 0.714… = 0.375 = 2.75 = 36.8 Any whole number is a number to the left of the decimal. Divide the denominator into the numerator. 6 9 4.66 4 = Ex: 7 1. 10 2 2. 9 5 3. 7 3 4. 8 3 5. 2 4 4 6. 36 5 Fractions to Decimals 4 + 0.66 = 0 .6 6 0 .0 - 54 6 0 - 54 6

5. Move the decimal to the right 2 places. If there are not enough numbers to fill the spaces add a ‘0’ to fill it in. Turn the Decimals into Percents 0.56 = 0.79 = 0.05 = 0.2 = 0.367 = 2.1 = Decimals to Percents = 60% 97% 0.97 = 0.6 0 56% 79% 5% 20% 36.7% 210%

6. Turn the decimals into fractions. 3.65 = 0.73 = 19.087 = Turn the Decimals into Percents. 0.71 = 0.3 = 0.08 = 0.276 = 73 100 65 100 3 87 1000 19 Warm Up - 2/4/09 71% 30% 8% 27.6% or 28%

7. Move the decimal to the left 2 places. If there are not enough numbers to fill the spaces add a ‘0’ to fill it in. Turn the Percents into Decimals 75% = 24% = 3% = 10% = 12.6% = 150% = Percents to Decimals = 0.01 0.32 0 1% 32% = 0.75 0.24 0.03 0.1 or 0.10 0.126 1.5 or 1.50

8. Fractions to Percents First turn the fractions into decimals. Then follow the process for turning Decimals into Percents. Percents to Fractions First turn the percent into a decimal. Then turn the decimal into a fraction. Fractions and Percents

9. Turn the Fractions into percents. Turn the Percents into Fractions. 25% 75% 33% 2% 4% 50% 2 3 9 4 1. 4. 3. 2. 11 10 4 5 25 5 75 2 4 50 33 100 100 10 100 100 100 100 or Fractions and Percents = 0.25 = = 0.75 = = 0.33 = = 0.02 = = 0.04 = = 0.5 = = 0.3 = 0.8 = 0.818 = 0.5 = 30% = 80% = 82% = 50%

10. Khadijah went to a sale at her favorite store. She found a jacket that was 20% off. If the original cost of the jacket was $150. How much money will she save? 20% of 150 150 x 0.20 = She would save $30. How much will the jacket cost? $150 - $30 = Taking a Percent of an Amount. Turn the percent into a decimal and then multiply the decimal by the amount. 1 20% = 0.20 150 x 0.20 30 0 2 0 0 0 0 3 0 0 0 + 00 0 0 0 0 3 0 0 0 $120

11. Bestbuy is having a sale. You found the CD you wanted for 30% off. The original cost was $17.95. What is the sale cost of the CD before taxes? 30% of 17.95 17.95 x 0.30 = You would save $5.39. Warm Up – 2/5/09 How much will the CD cost? $17.95 - $5.39 = 30% = 0.30 $12.56 2 2 1 5.39 17.95 x 0.30 0 3 0 0 0 0 0 5 3 8 5 0 + 0 0 0 0 0 0 0 5 3 8 5 0

12. Show your Work. 25% of 80 33% of 90 40% of 67 65% of 175 = 20 = 29.7 = 26.8 = 113.75 Find the percent of each amount.

13. Topics Covered So far • Decimals to Fractions • Fractions to Decimals • Decimals to Percent • Percent to Decimals • Fractions to Percents • Percents to Fractions • Percent of an amount

14. Target is having a sale on movies. Chris found the movie he wanted at a discounted price. He saved $8 off the original price of $25. What percent of the original price did he save? What are we looking for? The percent off. How do we find that? First lets look at another problem and come back to this one later. Percents

15. If Chris found the movie for 20% off and the original cost was $25. How much would he save? Remember that 0.20 is the same as 0.2 To make the multiplication easier use 0.2 Percents 20% of $25 25 x 0.20 = He would save $5.00. 20% = 0.20 5.00 1 25 x 0.2 0 2 5 0

16. Percents Target is having a sale on movies. Chris found the movie he wanted at a discounted price. He saved $8 off the original price of $25. What percent of the original price did he save? Back to our original problem. What are we looking for? The percent off. How do we find that?

17. When we wanted to find the amount of the discount we multiplied the percent off by the original cost. So to find the percent of the discount we do the opposite. Percents 25 x ______ = 8 What % 20% of $25 25 x 0.20 = You would save $5.00. If 25 x something = 8 then 8÷25 = that same something 20% = 0.20 5.00 For ex: 6 x 4 = 24 so: 24÷6 = 4 4 4

18. To find the percent of an amount when you know the original cost and the amount of the discount. Divide the discount by the original cost. Percents So to find the percent of the discount we do the opposite. 0 .3 2 0 .0 25 x ______ = 8 What % - 75 If 25 x something = 8 then 8 /25 = that same something 5 0 For ex: 6 x 4 = 24 so: 24/6 = 4 4 - 50 4 0

19. 8/25 = 0.32 0.32 = 32% So, he is saving 32% off the cost of the movie. Percents

20. 7 is what percent of 35? 12 is what percent of 60? 50 is what percent of 75? 42 is what percent of 84? 6 is what percent of 32? 20% 20% 66.7% or 67% 50% 18.7% or 19% Find the percent of the number

21. Michael went to buy a new video game for his Xbox 360. He found the game he wanted on sale for 35% off. The original cost was $49.99. What is the sale cost of the game before taxes? 35% of 49.99 49.99 x 0.35 = He would save $17.50. How much will the game cost? $49.99 - $17.50 = Taking a Percent of an Amount. Turn the percent into a decimal and then multiply the decimal by the amount. 2 2 2 4 4 4 35% = 0.35 49.99 x 0.35 17.50 0 3 5 1 2 1 4 1 9 9 5 1 4 9 9 7 0 + 0 0 0 0 0 0 1 7 4 9 6 5 $32.49

22. Turn the percents into fractions. 79% = 12% = 56% = Turn the Decimals into Percents. 2.51 = 0.07 = 0.7 = 0.329 = 12 100 79 100 56 100 Warm Up – 2/6/09 0.79 = 0.12 = 0.56 = 251% 7% 70% 32.9% or 33%