The 4x4x4 cube needs nine cuts if the pieces are kept together as a cube.
But by changing the piles..... the number can be reduced to 6.....
Well done Ironwood and Sij!

There a formula for a cube of 'n' sides but I can't work out how to post it. It reads:

For a nxnxn cube, the minimum number of cuts is 3k where k s defined as:

2 (to the power of k) is greater or equal to n which is greater than 2 (to the power of k-1)

They also considered block of n-dimensions with integral sides, which are to be sliced by a minimum number of planer cuts into unit hypercubes.....so there....

Useful they considered in the cheese and sugar loaf industries

Greg