The Weston High School Math Club just returned from an enjoyable and informative talk on “Mathematics and Magic Tricks,” presented by Prof. Persi Diaconis of Stanford University and sponsored by the Clay Mathematics Institute. As always — well, as we did once before — a group of teachers and students had dinner together at the Royal East Restaurant and then walked over to MIT for the talk. Diaconis, who has a well-deserved reputation as an entertaining lecturer, began with a truly impressive magic trick that he had invented, and then proceeded to elucidate the mathematics behind it and some other applications of various related mathematical ideas. There were several fortuitous connections with what I happen to be teaching right now in my precalculus class — including polynomials, number systems, bases, periodic phenomena, and functions — and what my students have learned previously in other courses, such as cryptography and DNA. Although this series of talks claims to be aimed at “the public at large,” this particular one was at the upper edge of appropriateness for my honors students, and last year’s left them behind. Not that that’s necessarily a bad thing — stretching one’s mind is undeniably useful — but I challenge the description.