What is the formula for percent increase?

Answer 1

You divide the difference by the original value, and the number you get is the percentage in decimal form.

Here's a word problem example! (oh what fun, right?)

You have 20 apples. Jane gives you more apples, until you have 25. By what percent did the amount of apples you have increase? (made by me, not stolen!)

Well, to find the difference is easy, 25 - 20 = 5

Now, you divide the difference by the original value: 5 / 20 = 0.25

0.25 is your percent in decimal form, to get the percentage, simply move the decimal to the right two places: 0.25 = 025, or 25%.