How do I solve a problem dealing with percentages?

Example: 10% of $50.00

It's become very frustrating because google says this is the formula: Sale price = Original price * (1 - Percent off%)

I really don't understand how the formula works.

Okay ...

Lets say you got a discount of 20% on a 40 dollar bike ...

To get the answer of how much off the bike is multiple 40 and 20%

In math if you are about to multiply a percent to a whole number put a decimal in front of it.

Example:

.20 * 40 = 8

So the bike is 8 dollars off

If you want to find the new price after the discount just subtract the answer (8)

40 (the original price) - 8 (the discount total)

The answer would be 32

The new price for the bike adding the discount would be $32. oo