Broken Calculator
A number puzzle on a calculator with broken keys. Build the target number using only the keys that still work.
How to play
- A target number is shown at the top of the screen.
- Keys marked with stripes are broken and cannot be pressed.
- Build an expression with the working keys and press "=". If the result matches the target, you clear the puzzle.
- While you type, a small preview shows the current result of your expression.
Expressions follow normal math order: multiplication and division first, then addition and subtraction. For example, "2+3×4" equals 14. Division does not have to come out even in the middle of an expression.
How stars work
The "Best" key count on screen is your target. If you use the same number of keys, you earn three stars. One extra key earns two stars, and anything more earns one star. Each digit counts as one key, even when you place digits side by side to make a larger number.
If you press "Show answer", one shortest expression is displayed. You earn no stars for that puzzle.
Stages and the daily puzzle
- Stages: Each time you clear a puzzle you move on to the next stage. In later stages fewer digit keys work, and even the shortest solution needs a longer expression. Puzzles are generated automatically, and every one can be solved.
- Daily puzzle: Each day there is one puzzle, set by the date. Everyone gets the same puzzle on the same day, so you can compare key counts with friends. Use "Copy result" to share your result.
Tips
- Place digits side by side. Even with few digits available, you can make two- and three-digit numbers.
- Get close with multiplication. Make a number near the target, then adjust with addition or subtraction.
- Overshoot, then subtract. Building a number that is too big and subtracting the difference is often a good route.
- Division is a tool too. Choosing numbers that divide evenly can produce surprising results.
- Use the preview. Check the running result to see whether you are getting closer.
FAQ
I can't press a digit after 0.
Numbers cannot start with 0, such as "05". Use 0 only as a number on its own.
Where is my progress saved?
Your stage and star count are saved in your browser only. They are not sent to any server.