Since many/most North Americans don't seem to know the Rule of Three, here's the easy way to calculate percentages
The Rule of Three is a really simple way to calculate percentages.
E.g. Say you want to calculate how much 5 is a percent of 10. You set it up like this:
5 --- ? <- The number you want to calculate the percentage for
10 --- 100 <- The number that you know the percentage for and what percentage it represents
Then you get the number you want to find the percentage for (5 in this case) and multiply it by the number diagonally opposite to it (100).
From there, you divide the result by the number across from the number you multiplied by (10)
5 x 100 = 500
500/10 = 50 5 is 50% of 10.
So long as you have 3 of the numbers you can do it to find the missing number.
e.g. 5 --- 50
10 -----?
10 x 50 = 500
500/5 = 100
