solving equations containing percents. percent proportion method part = % whole 100 example: what is...
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Solving Equations Solving Equations Containing PercentsContaining Percents
Percent Proportion MethodPercent Proportion Method Part = % Whole 100
Example: What is 25% of 20?
x = 25 You are trying to
20 100 find a “part” of 20
Proportion MethodProportion MethodExample: What is 18% of 56?
Part = % Whole 100%
x = 18% You are trying to
56 100% find a “part” of 56
Proportion MethodProportion MethodExample: 45 is what percent of 90?
Part = % Whole 100%
45 = x% You are trying to
90 100% find a percent
Proportion MethodProportion Method12 is 8% of what number?
Part = % Whole 100%
12 = 8% You are trying to
x 100% find the “whole” number
Proportion MethodProportion MethodWhat is 10% of 40?
Proportion MethodProportion MethodWhat is 30% of 62?
Proportion MethodProportion Method48 is 20% of what number?
THE PERCENT EQUATIONNS 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 MethodEquation MethodWhen 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 MethodEquation Method
What is 30% of 80?
n = 30% • 80
n = 0.30 • 80 REMEMBER to change
into a decimal!
n = 24
EX 1
Equation MethodEquation Method105 is what percent of 75?
105 = n • 75
105 = n•75 105 = 75n 75 75 1.4 = 140% = n REMEMBER to change into a
percent!
EXAMPLE: 2
Equation Equation MethodMethod
6 is 10% of what number?
6 = 10% • n
6 = 0.10 • n REMEMBER to change
6 = 0.10n 0.10 0.10
60 = n
EXAMPLE 3
YOU DO…YOU DO…What percent of 80 is 10?
n • 80 = 10
n • 80 = 10 80n = 10 80 80 n = 0.125 = 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!EXIT SLIP!Solving Percent Problems Using EquationsSolving 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; 2.28
24 = 40% • n; 60
13 = n% • 52; 25%
240 = 96% • n; 250
EXIT SLIP!EXIT SLIP!Solving Percent Problems Using EquationsSolving Percent Problems Using Equations
Equation MethodEquation MethodWhen 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 MethodEquation Method18 is what percent of 6?
Equation MethodEquation Method4 is what percent of 5?
Equation MethodEquation Method9 is 30% of what number?
Equation MethodEquation MethodWhat is 155% of 50?