Fun With One Cut!
At the 2013 TIME 2000 conference, I ran a workshop on mathematical folding called Fun With One Cut! Here are a few of the introductory slides.
In the workshop, students explored some basic properties of plane geometry through folding and tried their hands at the infamous fold-and-cut challenge: given a plane figure drawn on a piece of paper, is it possible to fold the piece of paper in such a way that the figure can be removed from the paper with a single, straight cut?
This is a fun, hands-on mathematical activity, and is connected to some surprisingly deep and rich results in both geometry and mathematical origami.