While your co-geeks may out this as a simple math trick, most people unable to recite pi past the decimal point will be amazed. It also has the advantage of requiring almost no physical, sleight-of-hand expertise.

1. Set the deck—from the top down, it should read 2, 3, 4, 5, 6, 7, 8, 9, A, A, A, A (the numbers in any suit and all four aces).

2. Shuffle, being sure not to affect the top 12 cards (yes, this is a cheap trick).

3. Ask an audience member to pick and state a number between 10 and 20 (not 20!).

4. Taking one at a time from the top of the deck, count that many cards into a face-down pile on the table.

5. Ask your dupe to add the two digits of his/her number and state the sum.

6. From your small pile, count that many cards back onto the top of your larger deck (throughout you will reverse and reinstate the original order—don’t lose it!).

7. The next card in your small pile is the first ace. Turn it face-up and leave it out.

8. Place the remaining cards in your small pile back atop the deck.

9. Fake another shuffle and repeat steps 3-8 two more times (finding two more aces).

10. To finish, ask you dupe to think of a number between one and nine, and then have him/her count that number of cards off the top of the deck, turning the last card face-up. If he/she picked the number nine, the card they turn over will be the ace.

11. If he/she did not turn over the ace (i.e. didn’t pick the number nine), then have him/her count additional cards from the deck, the number of additional matching the number on the card they overturned (i.e. if your dupe turned over a three, have him/her count off three more cards). The face-up card counts as the first! The last card dealt is the final ace.

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