Author: Scott Steketee

Collaborating on an Extension to a Little-Known Theorem

[Today’s post is from Steven Fuchs, with whom I recently corresponded and whose enthusiasm was sufficiently infectious that I pressed him to share it here. –Scott] One day late last spring, while teaching at St. Thomas High School in Houston, I noticed in a book a figure demonstrating Monge’s Theorem. (Don’t look this up yet;...

Polar Graphing

Using Sketchpad, it is very easy to start from scratch and create a polar graph. Here are the steps to create the graph shown on the right below. Choose Graph | Plot New Function. Use the Equation menu to choose r = f(θ). Type “c” (for “cos”), “2”, and “th” (for “theta”). Click OK. If your angle...

Cartesian and Polar Graphs

The Web Sketchpad model below (and here) shows the function f(θ) = 1 – cos 2θ in both Cartesian and polar form. For each graph, the independent variable appears as a red bar that corresponds to a particular value of x (for Cartesian) or θ (for polar). The red bar has tick marks that show...

Exponential Harmony with Sketchpad

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...

ICME: The Nature of Students’ Mathematical Thinking

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. But it turns out that my separation...

ICME: A Sensory-Motor Experience of Korea

I had the immense good fortune this year to attend ICME, the International Congress on Mathematical Education. The Congress is held every year divisible by 4, and this iteration (the twelfth) was held in Seoul, Korea. It is quite something to be at a meeting of nearly 4000 mathematics educators from 84 different countries, and...

Sketchpad Activities, Cognitive Demand, and Differentiation

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...

Parents, Children, and Functions in Sketchpad

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...

Writing Mathematics with Sketchpad

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...