Kids get their money

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...

Danny and Emily get their money...

Numberphile cancer research page: http://www.justgiving.com/numberphile-charity
Project for Awesome: http://www.projectforawesome.com/
Toilet twinning: http://www.toilettwinning.org/

The original Numberetti Video: http://www.youtube.com/watch?v=xYAU75IS40A