Snake cube Snake cube The snake cube is a mechanical puzzle, a chain of 27 or 64 cubelets, connected by an elastic band running through them. The cubelets can rotate freely. The aim of the puzzle is to arrange the chain in such a way that they will form 3 x 3 x 3 or 4 x 4 x 4 cube. A variation on the puzzle is a Kibble cube, which is also a string of cubes but has slots on the cubes. There are also many different styles of the cube. It can be made up of wood or plastic and
Cube (algebra) however, easy to show that most numbers are not perfect cubes because "all" perfect cubes must have digital root 1, 8 or 9. That is their values modulo 9 may be only −1, 1 and 0. Moreover, the digital root of any number's cube can be determined by the remainder the number gives when divided by 3: Every positive integer can be written as the sum of nine (or fewer) positive cubes. This upper limit of nine cubes cannot be reduced because, for example, 23 cannot be written as the sum of fewer than nine positive cubes: The equation has