Page 200 - Math Course 1 (Book 1)

Using Percent Equations

Mo. 6

Lesson 6

KEY CONCEPTS:
1. Solving percent problems using percent Let’s Begin
equations.
2. Solve real-life problems involving
discount and interest. Find the Part

Example

MO. 6 - L6a
Find 38% of 22. Estimate: 40% of 20 is 8.
Problem Solving: Words What number is 38% of 22?

Using Percent Equations

Variable Let n represent the number.
Vocabulary A-Z

Let us learn some vocabulary
Equation part = percent • whole or n = 0.38 • 22

n = 0.38(22) or 8.36 Multiply. Compare to the
estimate. Is the answer
Percent Equation reasonable?

is an equivalent form of a percent proportion in Answer 38% of 22 is 8.36
which the percent is written as a decimal.

Part
Whole = Percent
The percent is written as a decimal. Find the Part

Part Example
Whole • Whole = Percent • Whole
Multiply each side by the whole. 19 is what percent of 25?

4
19
Part = Percent • Whole Estimate: , which is 80%
=
5
25
This form is called the percent equation.
You know that the whole is 25 and the part is 19.
Let n represent the percent.
Concept Summary 19 = n(25)
19
The Percent Equation 25 = n Divide each side by 25.
0.76 = n Simplify.
Type Example Equation

Missing Part What number is n = 0.74(4)
75% of 4
Missing 3 is what percent 3 = n(4)
Percent of 4? 19 is 76% of 25. The answer
Answer makes sense compared to
Missing 3 is 75% of what 3 = 0.75n the estimate.
Whole number?
192