Today, we will create Hexaflexagons to introduce an area of mathematical study called topology. Topology is the study of the properties of geometric objects when folded, deformed, or stretched, but not cut or torn. NASA employs topology to create and deploy "starshades" and other technologies.
https://www.jpl.nasa.gov/edu/learn/project/space-origami-make-your-own-starshade/

Print and cut out your own hexaflexagon template of regular printer paper using this template:
hexaflex template copy paper
.pdf
Download PDF • 7KB
Here are the Vi Hart videos we watched in class to learn about Hexaflexagons:
http://vihart.com/hexaflexagons/
and a couple more if you are interested: