Chapter 41

Card tricks from permutations

Considermncards arranged in order, from left to right, and from top to
bottom. We call this the standard order.

1 2 3 4

5 6 7 8

9 10 11 12

13 14 15 16

Rearrangements with simple cycle structure lead to interesting card
puzzles. For example, the magician asks an audience to note the card at
a specific spot, rearranges the cards according to some simple rule, then
asks the audience to tell the new card at the spot. The magician is able
to tell the card that originally occupies this position.