Applications of Percents

Percent means one hundredth and it is denoted by the symbol % Percent means one hundredth and it is denoted by the symbol %. A percent can be expressed as a fraction and a decimal. Examples Percent Words Fraction Decimal 1. 15% Fifteen hundredths 15/100 .15 2. 6% six hundredths 6/100 .06 3. 125% One hundred twenty five hundredths 125/100 1.25

Changing Fractions to Decimals Examples 18/100= .18 2. 5/100 = .05 3. 175/100 = 1.75 When a fraction has a denominator that is a factor of 100, you form an equivalent fraction with 100 as the denominator. Then you multiply both the numerator and the denominator by the common factor to get the missing numerator. 24 = _?_ 2. 13 = _?_ 3. 15 = _?_ 4. 3 _?_ 50 100 20 100 25 100 5 100

Changing Decimals to Percents When you change a decimal to a percent, you shift the decimal point two places to the right and add a percent symbol. Examples .75 = 75% .09 = 9% .013 = 1.3% 1.35 = 135% 2 = 200% (Every whole number has an imaginary decimal point behind it. Remember $2 is the as $2.00) 6. 2.6 = 260% ( If there are not enough numbers when you shift the decimal point, you add zeros as needed for place holders.)

Changing Percents to Decimals When you change a percent to a decimal, you shift the decimal point two places to the left. Examples 1. 7% = .07 35% = .35 1.9% = .019 320% = 3.20 15.3% = .153

Let’s Practice! Write the following fractions as decimals 1. 11/100 = 2. 3/100 = 3. 44/50 = 4. 12/25 = 140/100 = 6. 15/20 = 7. 8/10 = Write the following decimals as percents 1. .13 = 2. .016 = 3. 1.5 = .06 = 5. .4 = 6. 5 = Write the following percents as decimals 1. 132% = 2. 6.9% = 3. 8% = 4. 16% = 5. 11.9%

Finding the Percent of a Number When you find the percent of a number, you change the percent to a decimal (by shifting the decimal point two places to the left) and then you multiply the decimal by the number given in the problem. * Remember your decimal rules for multiplication! Examples 1. 42% of 116 = .42 x 116 3% of 36 = .03 x 36 115% of 88 = 1.15 x 88 = 2.5% of 224 = .025 x 224 =