Use the slider to change the value of k, and to see dynamically how the graph of \(h(x)=k^x-x^k\) changes. Negative values have \(x^k>k^x\). Which value of k gives a graph that is never negative? Why? Here is a very pretty … Read More
The handshake problem is an old chestnut — if everyone in the room shook hands with everyone else, how many handshakes would there be? Then generalize. What I have to add to teaching the problem is a handout (doc version, … Read More
This is a great first day of class activity, which works well with math phobic students (I use it in a math for elementary teachers class). Students make a list 1:00, 2:00, etc. on a piece of paper — however … Read More
A video series.
This is a classic problem solving activity that I first saw many years ago in Mathematics: A Human Endeavor. The NCTM has a nice applet to test cases one at a time. Since I like playing with Excel and … Read More
I made this video when I was thinking about ways to teach the basics of linear transformations and matrices by illustrating their connections to computer graphics. I wanted to show the actual matrix calculations that lead to the graphics, as … Read More
Puzzle books I had as a kid often asked what the intersection of three cylinders looked like. Even looking at the answer in the back, I still had trouble seeing it. Making this video helped a lot. The Sketch Up … Read More
This is my first Sketch Up video. It is surprising how many shapes the cross-section of a cube can take on, and how hard they are to visualize (for most of us). The Sketch Up file I used is in … Read More
I start this activity by handing out buckets of tiles (any small objects will do) and asking students to take 10. They can sort their ten tiles into any number of piles, and their “prize” is the product of the … Read More
Explores some patterns in Pascal’s Triangle using Excel, including using conditional formatting to make a Sierpinski triangle. Excel Level: Beginning Plus (introduces conditional formatting). Math Level: Elementary – College.