Modular origami is so related to geometry, it could easily be used for a math fair project. This simple unit can create many, many polyhedrons (multiple sided objects, a cube being one example). This unit is one of those amazing units. It's a surprisingly easy module to make. However, you may need many pieces to create something truly extraordinary. Just a little patience is all it takes!
Fold a Penultimate Module
Slinky Guide