Write down the number you need wish to convert into a percentage.
Write below the number the total that the number is taken from. For example, if you took a test and got 75 correct out of a total of 90. You would write the number 75 at the top and 90 below it.
Divide the top number by the number below it using your calculator. For example, 75 divided by 90, which would equal 0.83.
Use your calculator to multiply the number you get by 100. This will give you the percentage. For example, 0.83 multiplied by 100 would equal 83 percent.