The cube above can be modified by removing balls. To remove a ball, point on it with the mouse and click. If you have removed wrong ball you can make it reappear using the [back] button. To remove balls from the other sides of the cube turn it using the [turn] button.

You can resolve the number of the balls used by applying the formulas you usually use for the volume count.

Enjoy.

designed by Witold Wojcik