[Every Monday for the next few months, we'll be posting a short video clip here at You Do the Math. All will have at least a tenuous connection to science, technology, engineering, or mathematics. Teachers can use these as writing prompts or as starting points for larger lesson plans (I'll try to include some hints now and then), but the main purpose is simply to have a little fun.]
In 1987, an otherwise forgettable Dick Clark production featured a number of tricks from mentalist Max Maven. This piece of interactive magic from the show makes for an interesting classroom exercise (though I might skip the first fifteen second -- somethings don't age well). I would print out copies so that the kids could each follow along at their desks. After running the video and having all of the kids play along, I would diagram out all the permutations and show how each path leads to the red circle.