Way back when I was a kid, my Dad showed me a card trick that had me baffled for a few days until I figured it out.
In this magic card trick, 7 hands of 5 cards are dealt out. The victim is then asked to pick a card out of the ones showing, and to tell the dealer which hand their card is in.
The cards are then reshuffled, and dealt out again in 5 hands with 7 cards in each hand.
The victim is then asked once more to signify which hand their previously chosen card is in.
Magically, the dealer turns over the cards and the victims card is identified.
SPECIAL NOTE TO REVIEWERS: Yes, this is a simple card trick, so, if you figure it out right away, good for you, but please refrain from spoiling it for other folks. Don't give details about how the trick works here. It's much more fun if people figure it out themselves.