Almost every kid loves shopping so how about going shopping. While looking for clothes you can look at the prices and if you want more of the same product just calculate how much it would be if you wanted four of one thing or 10 of one thing. Also if there's a discount then you can see how much it would be if it was maybe 20% off or something. Next all you have to do is add it all together and if you use a credit card or maybe a $100 bill then you can make out your own change so you'll know your not being cheated.