# Solving percent problems

In the last lesson, you worked on identifying the components of percent problems.  Today, let’s look at ways we can manipulate the formula for percent to find other components.

This is the formula you worked with a couple lessons ago.  If you know the PART and the WHOLE, you use this formula to find the PERCENT.

PERCENT =  PART / WHOLE

If you know the WHOLE and the PERCENT, you can use this format to find the PART:

PART = WHOLE x PERCENT

If you know the PERCENT and the PART, you can use this format to find the WHOLE:

WHOLE = PART / PERCENT

Let’s look at our examples from the last lesson and find the missing component.

Example 1

Chris ate 7 pieces of pizza.  There were 8 pieces of pizza to start.  What percentage of the pizza did they eat?

You are given the PART (7 pieces) and the WHOLE (8 pieces).  The unknown, the component you are asked to find, is the PERCENT.

You will use PERCENT = PART / WHOLE

7/8 = .875 = 87.5% of the pizza

Example 2

Alyssa’s reading assignment for this week is to read 200 pages.  She is 65% of the way through the assignment.  How many pages has she read?

You are given the WHOLE (200 pages) and the PERCENT (65%).  You are asked to find the PART.

PART = WHOLE x PERCENT

200 x .65 = 130 pages

Example 3

Daniel has read 6 books so far this year.  This is 20% of the goal he set for himself this year.  What is the goal he set for himself?

You are given the PART (6 books) and the PERCENT (20%).  You are asked for find the WHOLE.

WHOLE = PART / PERCENT

6/.20 = 30 books