Percent of change is used to measure a specific percent increase or decrease of an integer or measurement, such as a discount on an item, marking up the price of an item, or changing the size of a geometric shape. Basically, you find the difference between the original value and the new value and divide that difference by the original value. Voila, you have your percent of change.


An important thing to remember about percentages is that in many cases you can deal with percentages without knowing the original values of something. For example, an object can have its dimensions increased by certain percentages and you don’t need to know the original dimensions to find its percent of change.