A

David

Darling

Slothouber-Graatsma puzzle

The Slothouber-Graatsma puzzle is a packing puzzle in which six 1 × 2 × 2 blocks and three 1 × 1 × 1 blocks must be fitted together to make a 3 × 3 × 3 cube. There is only one solution. A similar but much more difficult puzzle, named after its inventor, John Conway, calls for packing three 1 × 1 × 3 blocks, one 1 × 2 × 2 block, one 2 × 2 × 2 block, and thirteen 1 × 2 × 4 blocks into a 5 × 5 × 5 box.