This is a self working version of the classic Triumph Card Trick.
The magician shows a pack of cards and begins to mix them in a most unusual manner, some cards are turned face up, others are turned face down. The result is a mixed up pack of cards where half the pack is face up, the remainder face down. The cards are spread and as the magician faces away, a card is selected, remembered and replaced. The magician now faces forward and gathering the cards, proceeds to mix them again. Then in a moment of inspiration, the cards are once again spread, the entire pack has righted itself with the exception of one card, that card is removed and revealed as the chosen card.
Easy to do, simple and direct magic. You'll use this right away.