Fractions, decimals and percents.

1. Fractions, decimals and percents.

2. Fraction – number of equal parts of a whole; a number usually expressed in the form: Definition: 3 Three 4 Fourths

3. Decimal - Any number shown with a decimal point; a number based upon tenths hundredths or thousands. ( 0.2, 0.375, 86.4 ) Definitions 0.05 of a Dollar 0.25 of a Dollar 0.10

4. Percent- The word percent comes from Latin and means “ for each hundred” or “ per hundred.” ( 70%, 6.5%, 4.09% ) Definitions Price: $5 40% off Price: $18 25% off Price: $90 20% off

5. How do I write fractions as decimals ? Use long division Divide the numerator by the denominator. * Numerator goes inside 0 0 6 6 . . 3 3 3 3 0 = = 5 5 5 5 - 30 0 * Denominator goes outside

6. Express as a decimal. You try: 0 7 5 . 4 3 .00 -28 0.75 2 0 -20 0

7. You try: 0.125 0.5 0.6 0.75 0.4 0.2 0.5 0.1 0.625 0.4

8. Converting Fractions to Percents To convert a fraction to a percent: • Change the fraction to a decimal ( by dividing the numerator by the denominator ). • Multiply the decimal by 100 and put a percent sign (%). Or move the decimal point two places to the right and put a percent sign (%). 0 0 4 4 . . 2 2 2 2 0 = = 5 5 5 5 - 20 0 0.4 x 100 = 0 4 0 % 1 2

9. Example 1: Convert 1/2 to a percent 0 0 5 5 . . 1 1 1 1 0 = = 2 2 2 2 - 10 0 0.5 x 100 = 0 5 0 % 1 2

10. Example 2: Convert 1/3 to a percent 3 3 0 0 3 3 3 3 . . 1 1 1 1 0 0 0 = = 3 3 3 3 - 9 It will keep repeating so add a repeating bar over the last two decimals 1 0 - 9 1 0 - 9 1 0.333 x 100 = 0 3 3 3 % 1 2

11. You try: 1. 0 0 = 100 % 0.8 7 5= 87.5 % 0.3 3 3 = 33.3 % 0.666 =66.6 % 0.6 0 = 60 % 0.08 = 8 % 0.8 0 = 80 % 1.75 = 175 % 2.2 0 = 220 % 0.36 = 36 %

12. Converting Decimals to Fractions First: In order to write a decimal as a fraction, read the number using place value. Second: The last word would be fraction’s denominator. Third: Then simplify if it is possible. 0.8 8 Eight tenths 10 Can you simplify this fraction? 2 4 8 0.8 = = 2 10 5

13. Convert 0.35 to a fraction: First: 0.35 Thirty five hundredths Second: 35 7 100 20 Third: 5 7 35 0.35 = = 5 100 20

14. Convert 0.625 to a fraction: First: 0.625 Six hundred twenty-five thousandths Second: 625 5 1000 0.625 = 8 Third: 25 5 25 625 5 = = 25 5 1000 40 8

15. 0.52= • 0.32= • 0.001= • 0.25= • 0.045= • 0.185= • 0.5= • 0.333= • 0.6= • 1.0= Now you try: 4 5 4 5 4 5 4 5 25 2 25 2 5 5

16. Converting Decimals to Percents To write a decimal as a percent: Multiply the decimal number by 100 and add the percent sign (%) which means move the decimal point two places to the right and write the percent sign (%). 0.789 x 100 = 0 7 8 9 % 1 2 0.789 = 78.9 %

17. write 0.28 as a percent 0.28 x 100 = 0 2 8 % 1 2 0.28 = 28 % write 0.9 as a percent 0.9 x 100 = 0 9 0 % 1 2 0.9 = 90 %

18. 0.5= 0.08= 0.205= 0.003= 0.0125= Now is your turn: 0.5 = 0 % 50 0.08 = 8 % % 0.2 0 5 = 20.5 0.0 0 3 = 0.3 % 0.01 25 = 1.25 %

19. Converting Percents to Decimals To write a percent as a decimal : Divide the decimal number by 100 and take away the percent sign (%) which means move the decimal point two places to the left and take away the percent sign (%). 78.9 %  100 = 0 7 8 9 2 1 78.9% = 0.789

20. write 28% as a decimal 28 %  100 = 2 0 8 2 1 28% = 0.28 write 5% as a decimal 5 %  100 = 0 0 5 2 1 5% = 0.05

21. 46%= 33.3%= 9%= 0.75%= 12.5% 2.5%= Converting Percents to Decimals

22. Converting Percents to Fractions To write a percent as a fraction, write the number over a 100 Then simplify if is possible. 8% = 8 100 2 25 4 2 8% = = 4 25 8 100

23. Converting Percents to Fractions To write a percent as a fraction, write the number over a 100 Then simplify if is possible. 25% = 25 100 25% = 1 4 5 5 5 1 = = 5 5 20 4 25 100

24. Converting Percents to Fractions To write a percent as a fraction, write the number over a 100 Then simplify if is possible. 125% = 125 100 125% = 1 4 5 5 25 5 = = 5 5 20 4 125 100

25. 46%= 33%= 9%= 75%= 12% 25%= Converting Percents to Fractions