Numbers Man

Alex Bellos discusses how the Incans used knots in string (Quipu) to record numbers.Check out Brilliant (get 20% off their premium service): https://brillian...

Author Alex Bellos tells us how he wrote a best-selling book about numbers. Check it at: http://amzn.to/1l0yX46

He wrote Alex's Adventures in Numberland, sold in the US as Here's Looking at Euclid.