I have often wondered how these whiz kids do mental gymnastics. I am talking about people, who have phenomenal memories and recite numbers backwards or do calculations at jet speed. How do they do it? The methodology seem simple. They either give characters to numbers or associate it with some other ordinary things. Alexis Lemaire, one of the latest in the long line of “human calculators” says, “I have these associations between places and numbers - some places are imaginary, I try to vary so I don't confuse the numbers”. British savant, Daniel Tammet set the world record for reciting pi at more than 22,000 digits also uses a method somewhat similar to that of Alexis Lemaire. “To him, each number has a distinct colour and appearance, some beautiful, some not, with each complex calculation making up a landscape”. Mike Byster another “human calculator” reveals, "I was always able to find patterns in things when I was a little kid”. Obviously all these “human calculators” are using the power of association, but it does not reveal how they spew out calculations with such rapidity. Ruediger Gamm: Mental ArithmeticBrain Man on 60 minutesNatural Born Mathematicians