The performer shows a flat square board bearing a single large spot on one side.Turning it over, the other side is seen to display six spots.
Reversing the board again, there are now three spots — and on the other side, now four!!
Another turn, and there are now two spots — and on the other side, five!! You’ve shown all six surfaces of a three-dimensional die, on a two-dimensional boar.
As a final surprise climax, the board expands into a cube — becoming a giant three-dimensional die!!