7-5 Percents Learn to write percents as decimals and as fractions.

7-5 Percents Vocabulary percent

7-5 Percents Most states charge sales tax on items you purchase. Sales tax is a percent of the item’s price. A percent is a ratio of a number to 100. You can remember that percent means “per hundred.” For example, 8% means “8 per hundred,” or “8 out of 100.”

7-5 Percents If a sales tax rate is 8%, the following statements are true: For every $1.00 you spend, you pay $0.08 in sales tax. For every $10.00 you spend, you pay $0.80 in sales tax. For every $100 you spend, you pay $8 in sales tax. Because percent means “per hundred,” 100% means “100 out of 100.” This is why 100% is often used to mean “all” or “the whole thing.”

7-5 Percents Additional Example 1: Modeling Percent Use a 10-by-10-square grid to model 17%. A 10-by-10 square grid has 100 squares. 17% means “17 out of 100” or. Shade 17 squares out of 100 squares ___

7-5 Percents Check It Out: Example 1 Use a 10-by-10-square grid to model 26%. A 10-by-10 square grid has 100 squares. 26% means “26 out of 100” or. Shade 26 squares out of 100 squares ___

7-5 Percents Additional Example 2: Writing Percents as Fractions Write 35% as a fraction in simplest form. Write the percent as a fraction with a denominator of 100. Write the fraction in simplest form. 35% = ___ 35 ÷ ÷ 5 _______ = 7 20 __ Written as a fraction, 35% is __

7-5 Percents Check It Out: Example 2 Write 65% as a fraction in simplest form. Write the percent as a fraction with a denominator of 100. Write the fraction in simplest form. 65% = ___ 65 ÷ ÷ 5 _______ = __ Written as a fraction, 65% is __

7-5 Percents Additional Example 3: Life Science Application Janell has 20% body fat. Write 20% as a fraction in simplest form. Write the percent as a fraction with a denominator of 100. Write the fraction in simplest form. 20% = ___ 20 ÷ ÷ 20 _______ = 1 5 __ Written as a fraction, 20% is. 1 5 __

7-5 Percents Check It Out: Example 3 Timmy has 14% body fat. Write 14% as a fraction in simplest form. Write the percent as a fraction with a denominator of 100. Write the fraction in simplest form. 14% = ___ 14 ÷ ÷ 2 _______ = 7 50 __ Written as a fraction, 14% is __

7-5 Percents Additional Example 4: Writing Percents as Decimals Write 56% as a decimal. Write the percent as a fraction with a denominator of 100. Write the fraction as a decimal. 56% = ___ Written as a decimal, 56% is – –600 0 To divide by 100, move the decimal point two places to the left. 56 ÷ 100 = 0.56 Remember!

7-5 Percents Check It Out: Example 4 Write 32% as a decimal. Write the percent as a fraction with a denominator of 100. Write the fraction as a decimal. 32% = ___ Written as a decimal, 32% is – –200 0

7-5 Percents Additional Example 5: Application Water made up 85% of the fluids that Kirk drank yesterday. Write 85% as a decimal. Write the percent as a fraction with a denominator of 100. Write the fraction as a decimal. 85% = ___ 85 ÷ 100 = 0.85 Written as a decimal, 85% is 0.85.

7-5 Percents Check It Out: Example 5 Water made up 95% of the fluids that Lisa drank yesterday. Write 95% as a decimal. Write the percent as a fraction with a denominator of 100. Write the fraction as a decimal. 95% = ___ 95 ÷ 100 = 0.95 Written as a decimal, 95% is 0.95.