This simple card trick (featured in Resonance – Journal of Science Education) is self working, meaning it requires minimal effort from the performer.
Performing the card trick
- Prepare a deck of 21 cards and arrange them into three face-up piles, each containing 7 cards. Invite a spectator to review the cards and mentally select one card while only pointing to the pile it belongs to.
- Carefully stack the three piles on top of each other, ensuring that the pile containing the spectator’s chosen card is placed in the centre. Now, deal the deck once again into three piles.
- Request the spectator to once more indicate the pile that holds their noted card. Repeat the procedure one more time. Something extraordinary is about to happen!
At this point, it can be observed that during the first time we pick up the three piles, the spectator’s card is somewhere between positions 8 to 14 in the deck. The second time, it resides within positions 10 to 12. The third time, it reaches the very centre of the deck (position 11). It is up to the performer how they reveal the chosen card to the astonished spectator.
This card trick works with decks of 15 or 27 cards too, raising the question: Can it also mesmerize with 51 cards?