Prodigies of mental calculation

Is this for real? Well, everyone's wired differently:

Alexis Lemaire used brain power alone to work out the answer to the 13th root of a random 200-digit number in 70.2 seconds at London's Science Museum.

The 27-year-old student correctly calculated an answer of 2,407,899,893,032,210, beating his record of 72.4 seconds, set in 2004.

The so-called 'mathlete' used a computer package to randomly generate a number before typing in the answer.

Mr Lemaire began demonstrating his mental calculation prowess by finding the 13th root of a random 100-digit number.

This feat soon became too easy for him and he abandoned trying to improve his time when he calculated an answer in less than four seconds in 2004.

From the BBC. More on how he does it here:

Lemaire explains that what he does is about transforming raw numbers into other structures so he can "see" the answer to the problem.

"When I think of numbers sometimes I see a movie, sometimes sentences. I can translate the numbers into words. This is very important for me. The art is to convert memory chunks into some kind of structure.

"I see images, phrases, actions. It's very tactile, sensitive. I have these associations between places and numbers. Some places are imaginary, I try to vary so I don't confuse the numbers. It's important to memorise. I have to be precise."

Lemaire's explanation is similar to that of British savant Daniel Tammet. Tammet set the world record for reciting pi at more than 22,000 digits at the museum in 2004.

To him, each number has a distinct colour and appearance, some beautiful, some not, with each complex calculation making up a landscape.

I have heard similar explanations from other mathematically gifted persons; ditto from the musically gifted. Alas, for me a number is just a number, a note, just a note.

Why the 13th root? Read more at Wikipedia, and at the 13th Root website.

Posted by David on December 12, 2007 8:40 AM