It has been suggested that this puzzle was a great favourite among the
young apprentices of the City of London in the sixteenth and seventeenth
centuries. Readers will have noticed the curious brass grasshopper on
the Royal Exchange. This long-lived ... Read more of THE GRASSHOPPER PUZZLE. at Math Puzzle.ca
Effect: A magician removes two cards from a deck and places them face up on the table. The deck is handed to the spectator where he/she will start dealing cards face down onto the table, when he/she stops, the magician places one face up card on top of the dealt pile and the rest of the deck is placed on top of that. The spectator again deals cards face down and when they stop, the magician places the other face up card at that point. Upon examination of the placement of the face up cards, the spectator sees he/she stopped dealing where the two "prediction" cards' twins were located.
At the beginning of the trick, take two "prediction" cards out of the deck. The prediction cards are actually the twins (hearts is twins with diamonds, spades/clubs) of the top and bottom cards of the deck. Remove the prediction cards and place them face up on the table. Instruct the spectator to deal cards into a pile face down and stop when they wish. When they stop place the twin of the card originally on the bottom of the deck onto the dealt pile face up. The spectator will then place the rest of the deck on top of the face up card. Have the spectator gather the deck and repeat dealing and when they stop place the other face up card at that point and have them put the deck on top of that. Run through the deck to find that the card to the right of each face up card is their twin.