Make 24 challenge
Combine four number cards using arithmetic to make 24 together.
How to use
Two to six people share one device and combine four number cards using arithmetic to make exactly 24. Five fixed, untimed questions allow negative numbers and fractions, with undo and confirmation before resetting or revealing one solution.
Start in three steps
- Read the rules and start the five questions. One person selects two different cards in order, then an operation. Subtraction and division use the first card followed by the second.
- Each combination preserves parentheses and original card sources. Use all four original cards once. Before finishing, undo steps or confirm a reset. Division by zero leaves the cards and undo history unchanged.
- Only a final card equal to exactly 24 counts as solved. Confirming a reveal marks the solution as viewed. Either outcome locks the question. Continue manually, then view the five results after question five.
Storage and limitations
Cards, expressions, undo history and results stay in page memory only. Leaving or refreshing clears them; nothing is written to the URL, persistent storage or a server. There are no custom questions, timer, rankings, accounts or multiplayer connection, and no educational outcomes are claimed.
Frequently asked questions
How are fractions and cards with the same number handled?
Exact rational arithmetic reduces each fraction and keeps its denominator positive. Success does not depend on floating-point tolerance. Each original card has a distinct ID, so equal numbers must still be used separately; you cannot select the same card twice.
Can a revealed answer count as solved?
No. Revealing asks for confirmation; cancelling keeps the current state. Confirming shows one solution and marks it as viewed. Solving or revealing locks cards, operations, undo and reset. Continue manually.
Can I enter custom questions or connect multiple devices?
This version has five fixed questions for people discussing around one phone or tablet, with one operator. There is no custom input, player management, multiplayer connection or ranking. Refreshing clears progress.