Figuring: The Joy Numbers Record Breaking Mathl Magic from World's Fastest Human Cmptr

Shakuntala Devi presentes math patterns in an interesting, accessible and playful manner. I teach elementary math to teachers, and I think I'll use these chapters to start their math minds working at the beginning of our sessions. I think they might do that with students as well.

Although the whole book is excellent, the multiplication chapter is the crowning achievement. Shakuntala teaches you how to cross multiply any two numbers in a very simple, straightforward way that is easy to learn and easy to do. And if you already know how to do Chisanbop (Fingermath), you will have a very powerful tool to do large multiplication problems without paper or pencil. She also does a ton of good stuff with all the other basic arithmatical operations. An great book that should be part of anyone's math library.