Hey Super Math Kids! Do you want to impress your friends and teachers with your amazing math skills? Imagine solving tricky multiplication problems in your head, without even needing a pencil or paper ...

What are you like at multiplications? Chances are if you're a mere mortal 2, 5s and 10s won't seem too taxing. But when it comes to figuring out what 42x21 is, you may wish somebody had shown you the ...