Chapter 7 – 3 Fractions, Decimals, and Percents Unit 3 Chapter 7 – 3 Fractions, Decimals, and Percents prealgebrateachers.com

Vocabulary A percent is a ratio that compares a number to 100. The meaning of 75% is shown at the right. In the figure, 75 out of 100 squares are shaded. prealgebrateachers.com

Percents as Fractions = 9 25 = 6 5 =1 1 5 = 5 1000 = 1 200 To write a percent as a fraction, express the ratio as a fraction with a denominator of 100. Then simplify, if possible. Note that a percent can be greater than a 100% or less than 1%. Express each percent as a fraction in simplest form Example 1: Example 2: Example 3: Multiply by 10 10 45% = 45 100 120% = 120 100 .5% = .5 100 to eliminate decimal = 9 25 = 6 5 =1 1 5 = 5 1000 = 1 200 prealgebrateachers.com

Write Fraction as Percent To write a fraction as a percent, write an equivalent fraction with a denominator of 100. Example 1: Example 2: 4 5 9 4 = 4 5 = 80 100 = 9 4 = 225 100 = 80% =225% prealgebrateachers.com

Let’s Practice! Write each percent as a fraction and a decimal Ex 1) 20% Ex 2) 85% Ex 3)110% Write each fraction as a percent Ex 4) 1 10 Ex 5) 2 5 prealgebrateachers.com

Let’s Check Our Answers! Write each percent as a fraction and a decimal Ex 1) 20% Ex 2) 85% Ex 3)110% 20 100 = 1 5 , .2 85 100 = 17 20 , .85 110 100 = 11 10 , 1.1 Write each fraction as a percent Ex 4) 1 10 Ex 5) 2 5 = 10% = 40% prealgebrateachers.com

Write Percents and Decimals To write a percent as a decimal, divide by 100 (or move the decimal two places to the left) and remove the percent symbol To write a decimal as a percent, multiply by 100 (or move the decimal two places to the right) and add the percent symbol prealgebrateachers.com

Write Percents as Decimal Express each percent as a decimal (Remember, divide by 100 or move the decimal two places to the left) Ex 1) 28% ----divide by 100 and remove the % 28% = 28% = .28 Ex 2) 8% Ex 3) 375% 8% = 8% = .08 375% = 3 7 5% = 3.75% prealgebrateachers.com

Write Decimals as Percents Express each decimal as a percent --- (Remember, multiply by 100 and add the % or move the decimal two places to the right) Ex 1) .35 Ex 2) .007 Ex 3) 1.35 . 35 = .35 = 35% .007 = .0 0 7 = .7% 1.35 = 1. 3 5 = 135% prealgebrateachers.com

Fractions as a Percent When expressing a fraction as a percent, express the fraction as a decimal then express the decimal as a percent Example 1) 5 8 Ex 2) 5 6 = .625 = 62.5% = .833333 = 83.3% prealgebrateachers.com

Remember… Fractions, decimals, and percents are all different names that represent the same number 1 2 .5 50% prealgebrateachers.com

Let’s Practice Write the percent as a decimal Ex 1) 50% Ex 2) 35% Ex 3) 2% Write the decimal as a percent Ex 4) .75 Ex5) .05 Ex 6) 1.15 Write the fraction as a percent Ex 7) 5 8 Ex 8) 1 3 prealgebrateachers.com

Let’s Check Our Answers! Write the percent as a decimal Ex 1) 50% Ex 2) 35% Ex 3) 2% =.50 .35 = . 02 Write the decimal as a percent Ex 4) .75 Ex5) .05 Ex 6) 1.15 = 75% = 5% = 115% Write the fraction as a percent. Round to the nearest tenth if needed Ex 7) 5 8 Ex 8) 1 3 = 62.5% = 33.3% prealgebrateachers.com