
This site has a variety of visual and calculation tools. Plot functioins, vectors, solve linear equations, and more.. From University of Colorado, Boulder math department. Use the help files at the top to get started. 

Wow! 59 Tutorials on College Level Algebra with practice tests! It includes everything from Long Division to solving NonLinear Equations. 

This program is a visual aid to learning and understanding simple fractions. 

This is a visual aid for learning about common denominators. 

Fill in the numerator and denominator and see a pie chart and percent. 

This program uses an animated tree diagram to demonstrate how to find prime factors. 

Use a balance scale to see how to solve a simple algebraic equation. 

Same as above but using negative numbers in the equations 

Drag triangles and boxes to fill figures, demonstrating the pythagorean theorem. 

See the effects on a graphic of applying translation, rotation, and reflection 

Watch different patterns form when you change the parameters for polygon fractals. 

Learn basic platonic solids by being able to shrink, rotate, and change their color. See them as wire diagrams or solids. 

See a Platonic solid drawn within another Platonic solid. Choose the Platonic solids as solid or wire diagrams, rotate them, and expand/contract them. 

Change values in a loan calculator and see a graph of the effects on payment of the loan. 