Author Archives

I am entering my 21st year as a math teacher at Weston High School, the sole public high school in Weston, MA. It’s also my 44th year as a teacher altogether. In addition to my day job, I taught for 20 years at the Saturday Course in Milton, MA. I also teach at Harvard’s Crimson Summer Academy each summer; 2017 was our 14th consecutive summer.

Sometimes I work on educational software. I also read, cook, and continue building my model railroad whenever I can. For some reason I'm left with less so-called free time than would be ideal. Nevertheless, I manage to devote time to my wife, Barbara, and to our excessive number of cats as well.

  • Comfort levels, parties, & structure

    Ordinarily I don’t feel very comfortable at parties if most of people are unknown to me. When most of the attendees are friends of mine, I’ll enjoy the party, but my comfort level goes down as the number of strangers… Read More ›

  • Helpful volunteers

    Three of my sophomore students have volunteered to set up a website for use by our Math Team. They’re designing a database to contain Math Team problems and answers collected from the last n years, typing many hundreds of problems… Read More ›

  • Notes on a textbook

    This note, written by a junior, was attached to the precalculus book she was returning: Dear Mr. Davidson, Here is my book. I have enjoyed it thoroughly. I read it when I was feeling down, and it raised my spirits…. Read More ›

  • Distribution of U.S. incomes

    Check out this interesting visual representation of U.S. income distribution. Try zooming out and out and out…

  • Life after exams

    It’s tough to keep kids focused and engaged after they’ve finished their final exams. As I blogged earlier, our math exams were on the 14th… but school continues until the 23rd! Everyone knows that tests and grades are all that… Read More ›

  • Fermat's Last Theorem limericks

    Weston High School held a math haiku contest, but maybe we should have had a math limerick contest instead. Here are some math limericks about the proof of Fermat’s last theorem (from a contest held at the University of Illinois… Read More ›

  • Cantor's proofs

    A lot of my precalculus students today didn’t like and/or didn’t believe Cantor’s proofs of the denumerability of the rationals and the non-denumerability of the reals. A few articulated their disbelief; most were quiet and attentive, but how many of… Read More ›

  • Stunning graphs of equations

    You have got to go look at the Visual Dictionary of Famous Plane Curves and study some of the stunning images that Xah Lee has collected. I particularly recommend his collection of sinusoids and his gallery of graphics based on… Read More ›

  • Beware the Algebrator

    Yes, there really is a product called The Algebrator. Their slogan is, “You Type in Your Homework Problem. Algebrator does the Rest!” Here is an excerpt from one of their ads. What’s wrong with this picture?

  • Too hot to think

    It wasn’t a great day for taking math exams. I opened up the windows and doors in my classroom at 7 AM to get some cross-ventilation, but when the exam started at 7:35 it was already 83 degrees in my… Read More ›