Funny Fractions and Ford Circles

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...

Farey Sequences, Ford Circles and a strange addition sign...
Featuring Francis Bonahon from the University of Southern California.

Watch EPIC CIRCLES: https://www.youtube.com/watch?v=sG_6nlMZ8f4

Periodic Videos chemistry: https://www.youtube.com/periodicvideos