Walks through a very nice example of the chi-squared test using a two way table. Explains degrees of freedom for this case.
Also discusses when a t-test can be used.
This applet from MIT allows you to select from 8 examples of differential equations. It allows you to select the step size. As you toggle through, the step size you selected traces out the "solution" in the vector field. You can then change the step size. It demonstrates the value of a small step size and also provides the actual solution.
Short video showing the relative volumes of a square pyramid and a cube with the same dimensions. Allows students to understand the origin of the volume formula for square pyramids.
Mu Alpha Theta is the National High School and Two-Year College Mathematics Honor Society. The link provides access to the top 8 student math videos for 2013.