15 and Hexadecimal

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...

Why is "f" a number to people who work with computers?

More about binary in our "Pac-Man" video at http://www.youtube.com/watch?v=umYvFdU54Po

This video features James Clewett.