Classic 24
Four cards from 1 to 9, target 24, only addition, subtraction, multiplication and division. The most widespread school version.
The addictive math game
🎲 Start gameYou get four random numbers to combine.
Add, subtract, multiply and divide with parentheses.
Your goal: use every number and reach 24.
You get 4 random numbers between 1 and 9. Your mission: combine them with addition, subtraction, multiplication, division and parentheses to reach exactly 24.
Each of the four numbers must be used exactly once. No more, no less.
Addition, subtraction, multiplication and division. Parentheses are your friends for tweaking precedence.
You can rearrange the numbers any way you like. There is no need to use them in the order shown.
The timer starts after the countdown. The faster you solve it, the better your personal best.
The 24 game, known in Chinese as 算 24 点 (suàn èrshí sì diǎn, “calculate 24 points”), became popular in 1980s China as a mental arithmetic exercise for primary school children. Its simplicity —four numbers, four operations, one goal— turned it into an educational phenomenon.
In 1988 the American mathematician Robert Sun patented a card-based version that brought the game to the Western world. Since then, international tournaments have emerged where top players solve each hand in under five seconds.
Today it is used in classrooms across the globe as a fun way to train numerical agility and mathematical creativity, and it features in many school olympiads.
Knowing a few shortcuts saves you a lot of time. Almost every combination opens up if you remember 24's divisors and play a bit with fractions.
24 = 1×24 = 2×12 = 3×8 = 4×6. Look for two numbers that already form one of these products and build the missing factor with the other two.
Products like 3×8, 4×6 and 2×12 appear over and over. If you spot a 3, ask yourself whether you can make 8 with the rest.
When nothing lands on round numbers, division saves you. For instance, 8 / (3 − 8/3) = 24 is the classic 3-3-8-8 puzzle.
If a number does not fit, find a way to turn it into 1 (multiplying by 1 changes nothing) or 0 (adding 0 doesn't either).
Four cards from 1 to 9, target 24, only addition, subtraction, multiplication and division. The most widespread school version.
Played with the whole French deck: J=11, Q=12, K=13 and the Ace usually counts as 1. Multiplies the variety of problems.
In the advanced mode, exponents and roots are allowed, opening up combinations that would be impossible in the basic game.
Instead of always aiming for 24, a different daily target is chosen. Great for keeping things fresh and ramping up difficulty.
Out of the 126 distinct combinations of four digits between 1 and 9, only two cannot be solved with addition, subtraction, multiplication, division and parentheses:
Our generator always discards these, so every game has at least one guaranteed solution.