Hexaflexagon

Orange, purple, green, orange, purple, g-- wait, how many sides does a piece of paper have? Why are there three colors?? These are hexaflexagons... a term I have heard every sixth period for the whole school year because my math teacher is obsessed with them.

There are some other fun videos that demonstrate why exactly these work, and some with even more than three sides! Check them out:
 https://www.youtube.com/watch?v=VIVIegSt81k

https://www.youtube.com/watch?v=paQ10POrZh8&t=4s

 

My math teacher also decided to have fun with this (as if these are not already fun) by showing us these funnier videos on hexaflexagons (warning, video four may cause hunger):

https://www.youtube.com/watch?v=AmN0YyaTD60

https://www.youtube.com/watch?v=GTwrVAbV56o