
Computation
Use
a deck of playing cards, a pencil and paper.
Instructions : Ask a participant to pick a card from the deck without revealing it to you. Double the face value of the card (ace = 1, Jack = 11, Queen = 12, and King = 13). Add 3 to their result. Multiply the result by 5. Add 1 if their card is a club, 2 if it is a diamond, 3 if it is a heart, and 4 if it is a spade. Ask them to tell you their number. To predict their card, subtract 15 from the final total. In the video we used the Queen of Diamonds. The right digit of the answer represents the suit of the card (1 = club, 2 = diamond, 3 = heart, 4 = spade). The left digit or digits is the number value of the card. For example, if their result is 83, the card is the 8 of hearts. If the result is 122, the card is the Queen of Diamonds. Challenge : Figure out how this trick works. Watch the video.
