Preview Warm Up California Standards Lesson Presentation

Write each fraction in the simplest form. Warm Up Write each fraction in the simplest form. 4 10 25 8 50 4 25 1. 2. 75 100 34 12 36 13 3. 4. 9 15 35 18 48 38 5. 6.

Preparation for NS1.4 Calculate given percentages of quantities and solve problems involving discounts at sales, interest earned, and tips. California Standards

A group of students plan to collect 2,000 cans of food for a food bank A group of students plan to collect 2,000 cans of food for a food bank. After 10 days, they have 800 cans of food.

The model shows that 800 out of 2,000 can be written as , , 200 400 600 800 1,000 1,200 1,400 1,600 1,800 2,000 1 5 2 5 3 5 4 5 5 0.2 0.4 0.6 0.8 1.0 20% 40% 60% 80% 100% 800 2000 2 5 The model shows that 800 out of 2,000 can be written as , , 0.4, or 40%. The students have reached 40% of their goal.

Additional Example 1: Writing Decimals as Percents Write 0.7 as a percent. Method 1: Use pencil and paper. 7 10 70 100 Write the decimal as a fraction with a denominator of 100. 0.7 = = Write the numerator with a percent sign. = 70% Method 2: Use mental math. Move the decimal point two places to the right and add a percent sign. 0.70 = 70.0% = 70%

Check It Out! Example 1 Write 0.3 as a percent. Method 1: Use pencil and paper. 3 10 30 100 Write the decimal as a fraction with a denominator of 100. 0.3 = = Write the numerator with a percent sign. = 30% Method 2: Use mental math. 0.30 = 30.0% Move the decimal point two places to the right and add a percent sign. = 30%

Additional Example 2: Writing Fractions as Decimals 5 8 Write as a percent. Method 1: Use pencil and paper. 5 8 = 5 ÷ 8 Use division to write the fraction as a decimal. = 0.625 = 62.5% Write the decimal as a percent.

Additional Example 2 Continued 5 8 Write as a percent. Method 2: Use mental math. 5  12.5 8  12.5 62.5 100 Write an equivalent fraction with a denominator of 100. = Write the numerator with a percent sign. = 62.5%

Check It Out! Example 2 3 5 Write as a percent. Method 1: Use pencil and paper. 3 5 = 3 ÷ 5 Use division to write the fraction as a decimal. = 0.60 = 60% Write the decimal as a percent.

Check It Out! Example 2 Continued 3 5 Write as a percent. Method 2: Use mental math. 3  20 5  20 60 100 Write an equivalent fraction with a denominator of 100. = Write the numerator with a percent sign. = 60%

Additional Example 3: Data Analysis Application If 27 out of 50 people surveyed have the newspaper delivered to their home, what percent of these people have the newspaper delivered to their home? 27 50 Set up a ratio. 27 out of 50 = Use division to write the fraction as a decimal. = 27 ÷ 50 = 0.54 = 54% Write the decimal as a percent. 54% of the people have the newspaper delivered to their home.

Additional Example 3 Continued Check Use estimation to check that the answer is reasonable. 27 50 ≈ , or 50% 25 1 2 Because 50% is close to 54%, the answer is reasonable.

Write the numerator with a percent sign. = 22% Check It Out! Example 3 If 11 out of 50 students surveyed have blue backpacks, what percent of the students have blue backpacks? 11 50 22 100 = 11 out of 50 = Write the numerator with a percent sign. = 22% 22% of the students have blue backpacks.

Check It Out! Example 3 Continued Check Use estimation to check that the answer is reasonable. 22 100 ≈ , or 20% 20 1 5 Because 20% is close to 22%, the answer is reasonable.

Lesson Quiz 1. Write 0.65 as a percent. 65% 6 10 2. Write as a percent. 60% 3. If 36 out of 80 people surveyed have been on a boat, what percent of these people have been on a boat? 45%