Find each number. Round to the nearest tenth if necessary. Do Now Find each number. Round to the nearest tenth if necessary. What percent of 60 is 15? 9 is 45% of what number? What number is 12% of 72

Objective: Solve problems by using the percent equations Chapter 8 Lesson 2 Algebra: The Percent Equation Objective: Solve problems by using the percent equations

The graph shows three main elements that make up most of the human body. 1. Suppose a person weighs 120 pounds. Use the percent proportion to find the number of pounds of oxygen, carbon, and hydrogen. Carbon 18% Other 7% 78 lb. 21.6 lb 12 lb Oxygen 65% Hydrogen 10% 2. Express the percent of each element as a decimal. .65 .18 .1 78 lb. 21.6 lb 12 lb 3. Multiply each decimal by 120. Round your results. Compare the answers to exercises 1 and 3. They are the same

Recall in lesson 7-8 Percent proportion Is Of X 100 = Part Base You used the percent proportion to find the missing part, percent, or base. You can also use an equation.

Today we are doing the same as we did in lesson 7-8 except instead of writing the problem as a ratio and then solving it, today we are writing it as an equation and then solving it.

IS means equals OF means X Recall IS means equals OF means X

Types of percent problems Example Proportion Equation Find the Part (IS) What number is 50% of 6? N = 50 6 100 N = 0.5 x 6 Find the Percent 3 is what percent of 6? 3 n 6 = 100 3 = n x 6 Find the Base (OF) 3 is 50% of what number? 3 50 N = 100 3 = 0.5 x n

Lets try some together!! N = 0.12 x 350 42 What number is 12 % of 350? Write an equation for each problem. Then solve. Round to the nearest tenth if necessary. What number is 12 % of 350? N = 0.12 x 350 42

Write an equation for each problem. Then solve Write an equation for each problem. Then solve. Round to the nearest tenth if necessary. 21 is what percent of 40? 21 = n x 40 52.5%

Write an equation for each problem. Then solve Write an equation for each problem. Then solve. Round to the nearest tenth if necessary. 13 is 26% of what number? 13 = 0.26 x n 50

Your turn!!! Write an equation for each problem. Then solve. Round to the nearest tenth if necessary. What number is 65% of 98? N = 0.65 x 98 N = 63.7

Your turn!!! Write an equation for each problem. Then solve. Round to the nearest tenth if necessary. Find 53% of 470. N = 0.53 x 470 N = 249.1

Your turn!!! Write an equation for each problem. Then solve. Round to the nearest tenth if necessary. 9 is what percent of 45? 9 = n x 45 N = 20%

Your turn!!! Write an equation for each problem. Then solve. Round to the nearest tenth if necessary. 26 is what percent of 96? 26 = N x 96 N = 27.1%

Your turn!!! Write an equation for each problem. Then solve. Round to the nearest tenth if necessary. 84 is 75% of what number? 84 = 0.75 x n N = 112