Miracle Dice (watch video). A small box is shown to contain 6 dice. The dice are showing the numbers 1 through 6 on top. The lid is replaced and an extra die is shown.
The spectator rolls the die. The dice and the box are shown to now MATCH the selected number! All six dice in the box change to match the selection before the lid is removed. Easy to do!
Miracle Dice (watch video)