Calculating cube numbers To calculate a cube number, you multiply a number by itself and then by itself again. For example, 3³ means 3 x 3 x 3. 3 x 3 x 3 = 27 Therefore, 27 is a cube number.

The first cube number is 1 because 1 × 1 × 1 = 1. The second cube number is 8 because 2 × 2 × 2 = 8. The third cube number is 27 because 3 × 3 × 3 = 27, and so on.

Their proof, however, relied on the equivalent of 35 years’ worth of number crunching on a good modern computer. For cubes bigger than the standard Rubik’s cube,… ...