Mr. Martin bought a microwave that was originally priced $225. He received a 30% discount. What is the sale price of the microwave.

I have a simple but slightly time consuming way of doing this. Find 30% of 100 double it and then find 30% of 25, add the two together ... In this case 60 + 7.5. After you do that subtract that number from 225. So subtract 67.5 from 225 and there is your answer. Your answer is 157.5