Subject: The world of percentage. Price tags everywhere

I know there is a formula to be utilized for finding the percentage of a number, like most math. You just simply need to remember the formula for finding the number. Please put me on the path.

How does one figure out 10% or 15% of a total number asked? Say... 120

What are the steps.

Reverse: 15 is what percent of 120, I know the answer should be the same but how is the formula applied?

Your help is needed.
Lydia

I think your problem here comes from the first sentence in your message. "I know there is a formula to be utilized for finding the percentage of a number, like most math." Very little of mathematics has to do with using formulas. One of the problems with seeing mathematics as a collection of formulas is that it is very easy to forget formulas.

For your question "How does one figure out 10% or 15% of a total number asked? Say... 120", percent means "per 100" (centum is the Latin word for 100) so 10% is 10 per 100, in other words 10/100. Thus 10% of 120 is (10/100)x120 = 12.

For the reverse "15 is what percent of 120" this can be rephrased as "15 is what/100 of 120". That is 15 = (what/100)x120. Now solve for "what". what = 15x100/120 = 12.5. Hence 15 is 12.5% of 120.