Krypto

Deck consists of 52 cards: three each of numbers 1-6, four each of 7-10, two each of 11-17, one each of 18-25. Deal five cards to each player, and a common objective card. Using basic arithmetic and each card exactly once, come up with a formula yielding the objective card. Winner is first to come up with a correct formula. Same mechanics can be used with a regular deck of cards, but the Krypto card distribution makes for a more interesting game.