How about this one.
Take a deck of cards. Don't look, but remove 3 of them and set them aside.
Start placing the rest of the cards face up on a table. Any cards that add up to 10 place more cards on top, like if you have a 5 and a 5, put cards on top of them.
Or, if there is a 10 put a card on top of that, in this trick, J+Q+K = 10. Ace+9=10 etc.
Once you are done, match up the piles where the top card equals 10 based on the rules above. You will be left with random stack where the top card didn't match up with another stack to make 10. Like 9, 6 and 2
The 3 cards you put to the side will be A, 4 and 8 (to make 10 with the stack that had no match)