Solving Equations Containing Percents

Percent Proportion Method Part = % Whole 100 Example: What is 25% of 20? x = 25 You are trying to find a “part” of 20

Proportion Method Example: What is 18% of 56? Part = % Whole 100% x = 18% You are trying to % find a “part” of 56

Proportion Method Example: 45 is what percent of 90? Part = % Whole 100% 45 = x% You are trying to % find a percent

Proportion Method 12 is 8% of what number? Part = % Whole 100% 12 = 8% You are trying to x 100% find the “whole” number

Proportion Method What is 10% of 40?

Proportion Method What is 30% of 62?

Proportion Method 48 is 20% of what number?

THE PERCENT EQUATION NS 1.4 Calculate given percentages of quantities and solve problems involving discounts at sales, interest earned, and tips. Objective-Students will calculate percentages using equations to solve percent problems by following steps, and scoring 80% on an exit slip.

Equation Method When do you have to change a decimal into a percent??? ◦ When you are finding a percent When do you need to change a percent into a decimal? ◦ EVERYTIME you have a percent in an equation you MUST change it into a decimal!

Equation Method What is 30% of 80? n = 30% 80 n = REMEMBER to change into a decimal! n = 24 EX 1

Equation Method 105 is what percent of 75? 105 = n = 75n = 140% = n REMEMBER to change into a percent! EXAMPLE: 2

Equation Method 6 is 10% of what number? 6 = 10% n 6 = 0.10 n REMEMBER to change 6 = 0.10n = n EXAMPLE 3

YOU DO… What percent of 80 is 10? n 80 = 10 80n = n = = 12.5% REMEMBER to change into a percent!

Write and solve an equation. 1.6% of 38 is what number? 2.40% of what number is 24? 3.What percent of 52 is 13? 4.96% of what number is 240? EXIT SLIP! Solving Percent Problems Using Equations

Write and solve an equation. 1.6% of 38 is what number? 2.40% of what number is 24? 3.What percent of 52 is 13? 4.96% of what number is 240? n = 6% 38; = 40% n; = n% 52; 25% 240 = 96% n; 250 EXIT SLIP! Solving Percent Problems Using Equations

Equation Method When do you have to change a decimal into a percent??? ◦ When you are finding a percent When do you need to change a percent into a decimal? ◦ EVERYTIME you have a percent in an equation you MUST change it into a decimal!

Equation Method 18 is what percent of 6?

Equation Method 4 is what percent of 5?

Equation Method 9 is 30% of what number?

Equation Method What is 155% of 50?