What colour is 27?

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...

More on number/color synesthesia, including your questions for with Alex Dainis.

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Blog with graphs: http://bit.ly/11yaWb8

Original video at: http://www.youtube.com/watch?v=dNy23tJMTzQ

Alex's channel is: http://www.youtube.com/user/Lexie527

Huge thanks to Dave Wiley!