Finding a percentage

Finding a percentage by expressing the rate as a decimal and multiplying it by the base is the goal of this lesson.

From the example in the image below, we have three important terms to define when finding a percentage.

Rate: The rate is the percent

Percentage: The result obtained when a number is multiplied by a percent

Base: The base is the amount you are taking a percent of

For instance,  take a good look at the following percent sentence:

40 % of 60 is 24

40% is the rate

60 is the base

21 is the percentage

Finding a percentage with a couple more examples

Example #1: Find 25% of 100

Percentage = Rate × Base

Percentage = 25% × 100

Percentage = 0.25 × 100

Percentage = 25

Example #2: What number is 75% of 200?

Percentage = Rate × Base

Percentage = 75% × 200

Percentage = 0.75 × 200

Percentage = 150

Example #3: x is 20% of 20. What is x?

Percentage = Rate × Base

Percentage = 20% × 20

Percentage = 0.20 × 20

Percentage = 4

Notice that you can also find the percentage by converting the rate into a fraction before multiplying it by the base. We show how to do this for example #1.

Example #4: Find 25% of 100

Percentage = Rate × Base

Percentage = 25% × 100

Percentage = 1/4 × 100

Percentage = 1/4 × 100/1

Percentage = (1× 100)/(4 × 1)

Percentage = 100/4 

Percentage = 25