Rules for 24

24 is a math card game from China where players race to combine four numbers to make exactly 24. The game has been popular in Shanghai since the 1960s and has since spread around the world. It is a good game for practising mental arithmetic and logical thinking.

The game works for 2 or more players and usually takes 15 to 30 minutes. You need a standard deck of cards with the face cards and jokers removed (40 cards in total). The goal is to be the first player to find a way to combine four numbers into 24.

Remove all face cards (Jack, Queen, King) and jokers from the deck. You should have 40 cards left: numbers 1 (Ace) through 10 in each of the four suits (♠️♦️♣️♥️).

For two players:

• Shuffle the cards thoroughly
• Deal 20 cards to each player, face down
• Players must not look at their cards
• Each player places their cards in a stack in front of them

For more players, the cards can be dealt equally among all players or placed in a shared stack managed by a dealer.

All players simultaneously take the top two cards from their stack and place them face up between the players. This gives four visible cards in total.

Everyone then tries to find a way to combine the four numbers to get exactly 24. You may use:

• Addition (+)
• Subtraction (-)
• Multiplication (×)
• Division (÷)
• Parentheses to control the order of operations

All four numbers must be used exactly once. You cannot join numbers together (for example, turning 2 and 3 into 23).

Here are some examples of how to solve different combinations:

• Cards: 3, 3, 8, 8
  Solution: 8 ÷ (3 - 8÷3) = 24
• Cards: 4, 1, 8, 7
  Solution: (8 - 4) × (7 - 1) = 24
• Cards: 2, 3, 4, 5
  Solution: (5 + 3 - 2) × 4 = 24
• Cards: 6, 6, 6, 6
  Solution: 6 + 6 + 6 + 6 = 24
• Cards: 10, 1, 8, 7
  Solution: (8 + 7) + (10 - 1) = 24

Note: some combinations have no solution under the standard rules.

When a player finds a solution:

1. The player slaps the table or calls out "24"
2. The player explains their solution out loud
3. The other players check that the solution is correct
4. If it is correct, the player wins the round
5. The winner takes all four cards and sets them aside

If no one finds a solution:

• Players can agree that there is no solution
• Each player takes back one of their cards and places it at the bottom of their stack
• New cards are drawn from the top of each stack

There are a few ways to keep score:

• Simple version: the first player to find a solution gets 1 point
• Advanced version: if a player declares no solution and another player then finds one, the finder gets 2 points
• Card version: play without points. The player with the fewest cards when one player runs out wins

The game can be played to an agreed total (such as 10 or 20 points) or until all the cards have been used.

24 can be played in several ways:

• Multiplayer variant: with 3 or 4 players, each player places one card. The first to slap the table must be chosen by the others to explain their solution
• Time limit: set a time limit (such as 30 seconds) for each round
• Advanced operations: allow powers and roots for an extra challenge
• Different targets: try to make 12, 36, or another number instead of 24
• Face card variant: include face cards with these values: Jack = 11, Queen = 12, King = 13

A few things that help when playing 24:

• Learn the factor pairs of 24: 1×24, 2×12, 3×8, 4×6
• Look for pairs of numbers that can produce these factors
• Try making 20 and adding 4, or 30 and subtracting 6
• If you have several identical numbers, experiment with parentheses
• Practise common patterns until they feel familiar
• Not every combination has a solution. Learning to spot impossible sets saves time
• Start with simple operations before working toward more complex solutions

24 is a useful tool in educational settings:

• Builds mental arithmetic and calculation skills
• Trains logical thinking and problem-solving
• Deepens understanding of how numbers relate to each other
• Encourages concentration and focus
• Works well for mathematics lessons in schools
• Suitable for most players from around age 8 and up
• Can be adjusted to suit different skill levels

The game is used in schools and maths clubs around the world as a practical way to make arithmetic practice more engaging.