How do you subtract percents from whole numbers?

Answer 1

A percentage can represent a fraction (like 50% = 1/2); however, percentages represent a portion of something else. So percentages are not under normal circumstances just subtracted from a number.

So say you have something like: How much is 30% off from $80 (or it might say 30% off of $80). This means there will be a subtraction, but you do not do it like change 30% to 30/100, then subtract to get $79.70.

The 30% is a portion of the original amount, so it is first multiplied by $80: (30/100) x 80 = 24. So it is $24 that you are taking off from the $80.

The 30% discount represents $24, and when you take 30% off, the new price is [$80 - $24 = $56].

If you are adding a percentage (like sales tax), you multiply the percentage by the amount, then add that to get the total sales price. So in our example, say the tax is 5%, we multiply (5/100) x the sales price of $56 = $2.80, then add $2.80 tax to $56 = $58.80