Numbers to Percents

[Anon]

Hi I dont really know how to do this.. I have a general idea.. but I am still lost. Now I would like to get a number and turn it into a percent based off the main number. Example.

Main number = 15
My number = 4

So how would I go about getting that percent?

Thanks for your time
Dan

[Anon]

Percentage=my number/main number*100