The 24 Game is an arithmetic card game in which players use four numbers to make 24.
In the classic version, four playing cards are dealt, with aces counting as 1 and face cards removed. Players must use all four values exactly once, combining them with addition, subtraction, multiplication, division, and parentheses. For example, the numbers 4, 7, 8, and 8 can produce 24 with (7 − 8 ÷ 8) × 4.
The puzzle is associated with Shanghai, where it was played as a card game from the 1960s. It has since appeared in classroom activities, puzzle books, competitions, and commercial editions. Some versions permit extra operations such as square roots or exponents, but those are extensions rather than the basic rules.
A frequent mistake is assuming any expression that contains the four numbers qualifies. It does not: every number must be used once, and the result must be exactly 24. Rummikub is a tile game, Cribbage is a scoring card game, and Set is a visual pattern-recognition game.