Magic Trick with math
I shuffle the cards. I put 26 cards face-up, secretly remembering the seventh card face-up, Jack of Hearts. I turn the 26 cards face down and place it back at the bottom of the deck. I place out three cards face-up (which is a three, a nine, and a two). I add a certain number if cards to each pile to make each pile add up to ten. Finally, I add the three cards which add up to fourteen. Where is the Jack of hearts?