Snake cube can vary in colour, material and size. The name comes from how the puzzle looks before and after it is solved. Before it is solved it looks like a snake and when it is solved it is a 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
Principal root of unity Principal root of unity In mathematics, a principal "n"-th root of unity (where "n" is a positive integer) of a ring is an element formula_1 satisfying the equations In an integral domain, every primitive "n"-th root of unity is also a principal formula_3-th root of unity. In any ring, if formula_3 is a power of formula_5, then any formula_6-th root of formula_7 is a principal formula_3-th root of unity. A non-example is formula_9 in the ring of integers modulo formula_10; while formula_11 and thus formula_9 is a cube root of unity, formula_13 meaning that it is not a "principal" cube