Percentage of a number- Two ways to solve   

1) set up a proportion        %     =   part           

                                           100        whole

2) change the percentage to a decimal and multiply, this can only be used when the whole is given and you are looking for a part.

Ratio-     Comparison of two quantities      

1. ex) there are 2 boys and 6 girls riding the carnival ride. What is the ratio of boys to girls?

         2:6   or 1:3     (boys goes first then girls because boys is before the word to)