8-7 Percents Course 1 Warm Up Warm Up Lesson Presentation Lesson Presentation Problem of the Day Problem of the Day

Warm Up Write each fraction as a decimal Write each decimal as a fraction Course Percents 3 4 __ 9 10 __ __

Problem of the Day Wally wanted to change the scale of a drawing from 1 in. = 2 ft to 1 in. = 10 ft. The scale height of a building in the first drawing is 25 in. How high is the building in the new drawing? 5 in. Course Percents

Learn to write percents as decimals and as fractions. Course Percents

Vocabulary percent Insert Lesson Title Here Course Percents

Course 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.”

Course 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.”

Course 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 ___

Course Percents Try This: 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 ___

Course 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 __

Course Percents Try This: 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 __

Course Percents Additional Example 3: Life Science Application Janell is an ice skater with 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 __

Course Percents Try This: Example 3 Timmy is a football player with 10% body fat. Write 10% as a fraction in simplest form. Write the percent as a fraction with a denominator of 100. Write the fraction in simplest form. 10% = ___ 10 ÷ ÷ 10 _______ = 1 10 __ Written as a fraction, 10% is __

Course 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!

Course Percents Try This: 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

Course 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.

Course Percents Try This: 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.

Lesson Quiz Write each percent as a fraction in simplest form % 2. 29% Write each percent as a decimal %4. 86% 5. A store clerk has an 8% sales increase. Write the increase as a fraction in simplest form and as a decimal. Insert Lesson Title Here, 0.08 Course Percents __ ___ __