Rubik's Cube
The Rubik's Cube is a logic puzzle in the shape of a cube that is cut twice along each axis to allow the faces of the cube to be twisted. Each face is coloured differently so that when a face (or slice) is turned, part of the adjacent faces also turn. This "scrambles" the puzzle and sets up the player to rearrange the movable parts to restore the "solved state" where each of the coloured faces is complete.
NB: this is a huge subject and so from here I will concentrate on how we at Nottingham Hackspace have enjoyed the cube and how we teach solving the cube in our workshops.