Wolfram Research
Wolfram Math World: Cube
Drawings and discussion on the properties of the cube, with lots of links to related pages. With this page you can find how to make a cube out of tetrahedron. [Requires Java.]
University of Cambridge
University of Cambridge: Nrich: Up and Down Stairs
Work with this cube problem and see if you can find a pattern. Then you can check your solution with solutions already submitted.
University of Cambridge
University of Cambridge: Nrich: Cubes Within Cubes
On this one page website sharpen your logic, geometry, spatial thinking, and problem solving skills while working on this challenge. The solution is available to double check your solution.
Other
Mathsteacher: Cubes
The lesson examines cubes through definitions and examples. Properties of cubes and the cube of a negative number are also explored.