This game for one to four players uses a deck of cards to develop mental addition skills. Cards are turned over in a row, and when the sum of cards on the ends of the row is 10, 20, or 30, a player can take those cards (aces count 1, face cards count 10). The winner is the player with the most cards at the end. For the solitaire version, the player must end with more cards than are left on the table. Variations include making jokers wild, or aces worth 11.