# 8.3.2 Percent Decrease

Whether it’s coupons you receive in the mail or a raise in your salary, you know that percentages are used to describe increases or decreases.

For example, suppose last week a pair of sneakers cost $125, and this week the same pair costs$100. The price decreased by \$25, which is referred to as the actual decrease.

To express the discount as a percentage, first write the actual decrease as a fraction of the original cost, then change the fraction into a percentage.

So the percent decrease is:

In other words, the price of the sneakers dropped by 20%. The process for calculating percent increases and decreases can be summarized as follows: .

8.3.1 Percent Increase/Decrease

8.3.3 Ups and Downs