Right before each school year begins, my colleagues and I meet with our incoming first-year students. We show them around the building, introduce them to the student groups, and generally just try to be welcoming. This past year, I decided my contribution to this event would be a magic trick from CS Unplugged.
Since one of my goals was to impress my future students, I needed to practice the trick a lot before they arrived. I wrote this little tool to do so.