Like other enthusiasts of mathematics, I’m captivated by the way that mathematical ideas can explain things in the physical world around me, and by the way that I can carry out mathematical thought experiments in my mind and then apply the results to control my external physical environment.
Harry Parker died this summer, two weeks after coaching the Harvard rowing team to yet another sweep of all four races (varsity, JV, freshmen, and spares) against Yale and two days after accompanying his 1980 Olympic … Continue Reading ››
After writing yesterday's post on the connections between polar and Cartesian graphs, I realized that I hadn't said anything about how easy it is to start from scratch and create a polar graph in Sketchpad, so I decided to write this post, and include an instructional video. Here are … Continue Reading ››
The May 2013 Mathematics Teacher has an excellent article by Jonathan F. Lawes ("Graphing Polar Curves") on the value of plotting the same function in both polar and rectangular coordinates. Doing so not only helps students understand how polar coordinates work, but also gives them a novel and revealing … Continue Reading ››
Last week was the fourth session of my spring Advanced Secondary Math Methods class at the University of Pennsylvania. Each year I assign a semester project in which groups of three students use lesson-study techniques—on a small scale—to create, test, refine, teach, evaluate, and document specific shared instructional products, composed of a (possibly multi-day) lesson … Continue Reading ››
Not long ago, I conducted a Saturday morning PD session for some Texas teachers participating in an NSF research project. (The research is a controlled study of the relationship between students’ use of Sketchpad and their conjecturing and proving behavior. I hope we’ll have a blog post about this study itself before too long.) Because of the … Continue Reading ››
Functions are hard for students. Students seem to master various families of functions – linear, polynomial, exponential, trigonometric, and so forth. They can graph them, evaluate them, transform them, and answer a variety of questions about them. But ask even our better students a question that’s out of the ordinary and we’re likely to be taken … Continue Reading ››
In a recent blog post, Karen Coe referred to Conrad Wolfram’s opinion that programming is to mathematics what composition is to English. I’ve taught programming and written a lot of Sketchpad code, and I appreciate Wolfram’s analogy. In English class, students read books, poems, short stories, essays, and articles—but to gain a deep appreciation for … Continue Reading ››