# Percent Change Formula

Percent Change Formula
$PercentChange=\frac{NewNumber-OriginalNumber}{OriginalNumber}\cdot 100$

Percent change calculates the percent increase or decrease. If the number is positive, it is a percent increase. If the number is negative, the percent change is a percent decrease.

Example 1:

A theater's ticket sales increased from 4,250 to 5,621 tickets sold from one weekend to the next. What is the percent change?

Step 1:

Determine which is the original number and which is the new number.

Original: 4,250

New: 5,621

Step 2:

Substitute and simplify.

$%Change=\frac{5621-4250}{4250}$

$%Change=\frac{1371}{4250}$

Step 3:

Divide and convert to a percent (multiply by 100)

$\frac{1371}{4250}=.32=32%$ increase since it is positive.

The number of tickets sold increased by 32%.

Example 2:

At this same theater, a movie's ticket sales on opening weekend were $30,850. The following weekend's sales were$22,360. What was the percent change?

Step 1:

Determine original and new numbers.

Original: 30,850

New: 22,360

Step 2:

Substitute and simplify.

$%Change=\frac{22360-30850}{30850}$

Step 3:

$%Change=\frac{-8490}{30850}=-0.28=28%$ decrease since it is negative