I had a math happening today! My nephew told me excitedly that he’s been wanting a big screen TV and saw that the Big TV Store was having a 20% off sale, discounting 20% less than the retail. He has a coupon for 30% off the sale price. The TV he wants is $600. He boasted that he will get a great deal with a decrease of 20% +30%=50% of the price, just $300! How should I break it to him that there is something wrong with his calculation? What’s the problem?