Count On Me is a great mathematical card tricks and can be performed with any deck of cards.

The Effect: The magician can reveal a chosen card even when it is selected with his back turned.

Method: With your back turned to them, ask a spectator to shuffle his own pack of cards and count off any number of cards as long as it is less than 15. If, for example, they choose number 5 then they look at the fifth card, they remember it and then they must replace the cards in the same order.

Then you turn around and take the pack, placing it behind your back. Count off 15 cards from the top putting them on the bottom but you must be careful not to reverse their order when you count them. At this point you can make it look as if you are fumbling around and unable to find a card. Next, hand the pack back to the spectator and tell them to transfer from the top to the bottom of the pack the same number of cards that they counted at first but before they do this, they are to check that their card is not anywhere near this position.