Book excerpt: Discover the adventure and excitement of mathematical puzzles. Match your wits with the human computer. Sharpen your intellect, delight your friends and enjoy hours of purposeful entertainment. Mathematics is not always hard, mind-boggling stuff. It can also be simple, delightful and interesting. Many famous mathematicians are known to be devoted to peg jumping puzzles. It is perhaps this kind of play that leads to scientific discoveries. The celebrity author, Shakuntala Devi, is regarded as 'authentic heroine of the twentieth century'. She calculates faster than the fastest computer, is listed in the Guinness Book of World Records and continues to amaze audiences around the world with her feats of calculation.