Percent (Concepts & Computation) Dec. 2

Introducing Percent Percent is a ratio of a number to 100. The symbol for percent is % Percent means “per hundred” 17 So, ------- is 17% 100

Finding Percents and Decimals 27 Ratio; ----- 100 Percent; 27% Decimal; 0.27

To write a percent as a decimal, move the decimal point two places to the left. Drop the percent sign. 51% = 51. = 0.51 2% = 02. = 0.02 15.6% = 15.6 =0.156

To write a decimal as a percent, move the decimal point two places to the right, write the percent sign. 0.82 = 0.82 = 82% 0.03 = 0.03 = 3% 0.319 = 0.319 = 31.9%

Exercise Write each percent as a decimal 63% = 63. = ___ 6% = 06. = ___ 22.3% = 22.3. = ___ Write each decimal as a percent 0.66 = 0.66 = ___ 0.02 = 0.02 = ___ 0.163 = 0.163 = ____

Percents and Fractions To find the percent for any fraction, you can divide the numerator by the denominator to find the decimal. Then you can write the percent Find the percent for ½ Divide 1 by 2 = 0.5 0.5 = 50%

Exercise Write as fraction, whole numbers, or mixed numbers. Show the answers in lowest terms. 1% 70% 400% 150% 57% 89% 175% Write as percents. 9 67 3 4 3 ---- ---- --- ---- 1 --- 100 100 10 25 20

Finding Percent using Mental Math fraction think example 200% 2/1 Multiply by 2 200% of 10 100% 1/1 Multiply by 1 100% of 3 50% ½ Multiply by ½ or divide by 2 50% of 8 25% ¼ Multiply by ¼ or divide by 4 25% of 16 10% 1/10 Multiply by 1/10 or divide by 10 10% of 460

Exercise 200% of 60 25% of 12 50% of 28 10% of 30 100% of 15 25% of 32