Word Lesson: Percent Increase and Decrease

By S Taylor

In order to solve problems that deal with percentage of increase or decrease, you should be able to:

change a fraction or a decimal to a percent
work with the formula for percent increase or decrease

When a beginning and ending amount are given and you are asked to find the percent of increase or decrease from the beginning amount to the ending amount, you need to use the formula shown below:

In other words, find out how much the increase or decrease was. Then divide that by the original amount given in the problem. Once you have this number as a fraction or a decimal, change it to a percent to find your answer.

Suppose the average attendance at a local high school's football games went down from 2000 people in 2003 to 1500 people in 2004. What was the percent decrease in attendance at the football games?

The solution to this problem begins by finding how much the decrease was.

This is done by taking 2000 - 1500 = 500.

So the amount of decrease is 500.

Now we divide that number by the original amount, or the football attendance in 2003, which was 2000.

So the conclusion is that football attendance decreased by 25% from 2003 to 2004.

The enrollment at a university increased from 14,000 students to 16,000 students over a period of 5 years. What is the percent increase in enrollment?

The selling price of a home was dropped from $200,000 to$ 190,000. By what percent did the price drop?

What is the percent decrease on a DVD recorder that is marked down from $400 to$ 350?

87.5%
12.5%
14.29%

My real estate agent told me that my house had appreciated in value over the last three years. In other words, it has gone from being worth $102,500 to being worth$ 111,000. What is the percent increase in the value of my house?

8.29%
2.76%
7.66%