Four Cards Pro for Android is a popular card game in China. Four cards are dealt and the player orders them and three math operators to equal 24. To play, drag the cards and operators to the chosen positions. Each card can only be used once, but math operators can be repeated. Only whole numbers zero or greater can be calculated. Tapping on a card or operator in the equation removes that item. The numbered cards are equal to their face value with A = 1, J = 11, Q = 12 and K = 13.