Applets are small, single-purpose computer programs, usually available on the Web through a browser. For this site, I built the applets in GeoGebra, with the goal of making various mathematical ideas more visual and more interactive. However you cannot expect them to teach the concepts they illustrate! They are most effective if they are part of a multidimensional pedagogy that gets students to engage intellectually rather than watch passively.

You can use the applets online, and/or download the corresponding GeoGebra files and modify them to better fit your needs.

Some links below are to a single applet, others are to a launch page with links to several applets.

### Algebra

Changing a, b, c in `y=ax^2+bx+c`

Complex Number Arithmetic Games

Constant Sums, Constant Products

Factored Form of a quadratic

Off and On, understanding linear inequalities

Stairs, slope puzzles

### Fractions

### Functions

Doctor Dimension, exploring rate of change

Function Diagrams, a parallel axes representation

- Iterating Linear Functions:
- with a table
- with linked function diagrams
- with a 'cobweb' graph
Iterating `f(x)=rx(1-x)` (in two representations)

### Geometry

Only four kindsSSASum of the Angles in a Triangle

Tri, Tri Again (inscribed circle iteration)

### Other

Pent, a two-person strategy game

Penumbra, some of the geometry of eclipses

Spirograph, exploring symmetric figures created by a circle in a circle

As I create more applets, I'll try to remember to add links in this directory.