How to Figure Out a Percentage?

Okay say you have 50 apples and you give away 20 of them and you want to know what percentage you have left. Subtract 20 from 50 and you get 30. Now divide the 30 by 50 and you get 0.6. Now simply move the decimal place of 0.6 two places to the right and add a percent sign and you have 60%.