Its anynumber (cubed) man, 1 cubed = 1
2 cubed = 8
3 cubed = 27
4 X4X4 = 64
5 cubed = 125
5X5X5

Here is an odd thing about this question it is intended to show cubes, but mistakenly adds a second answer in 46.

1 - 8 - 27 - X - 125 - 216. The best answer is 4^3. (64) It is the simplest solution.

Here is why 46 also works.

The difference between 1 and 8 … Read more

1 - 8 - 27 - 64 - 125 - 216 Series of cubes. 1^3 = 1, 2^3 = 8, 3^3 = 27, etc.
Comparable to the easier-to-recognize series of squares: 1 4 9 16 25 36 etc.