How do you write a ratio as a percent

A ratio is pretty much a fraction

Divide the numerator and denominator. You may or may not get a decimal. Move the decimal point over too the right two place values. You will then get a percentage. If it is a whole number, add two zeros behind and you'll get your percentage.

For example: 

10:2 is my ratio

10:2 is the same as 10/2 = 5

5 is the same as 5.00

move the decimal point to the right two place values

5.00 = 500%

hope this helps