Lace Knot Trick

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...

Playlist of Tadashi Tokieda videos: http://bit.ly/tadashi_vids

More knot videos: http://bit.ly/Knot-a-Phile

Fast shoelaces: https://youtu.be/XPIgR89jv3Q

What is a knot?: https://youtu.be/aqyyhhnGraw