Card Spelling Trick
(a Josephus problem)

Take the 13 cards of one suit for your deck.

Arrange them in such a way so that the following occurs:
Spell A - C - E, moving the cards to the bottom of the deck.
When you say "E", turn it up -- it is an Ace.
Continue, saying T - W - O. You would move two cards to the bottom of the deck, but when you say "O", you turn it up and reveal a "2".
Continue, saying T - H - R - E - E, moving 4 cards to the bottom and turning up a "3".
How do you arrange the 13 cards?

Q 4 A 8 K 2 7 5 10 J 3 6 9

While explaining the activity, I demonstrate with an oversize deck of cards.
Then, I give each student a suit of cards to work on.

Links:

Card Tricks

Math Tricks

Mr. P's Puzzles and Games Page