Equation Guess is a free online maths word game that runs in your browser with no download and no account. Somewhere behind the board is a true arithmetic sentence — something like 12+35=47 — and you have six guesses to find it. Every guess has to be a true sum itself, which is the rule that makes this a different game from guessing a word: you cannot probe with nonsense, so each attempt has to be both a real sentence and a question worth asking. What comes back is a colour for every character. Green means that digit or sign is exactly there; purple means it is in the sum but somewhere else; grey means it is not in it at all. The marking is careful about repeats, which is where most versions of this go wrong — if the answer holds one 3 and your guess has two, only one of them can come back purple, because telling you there is another 3 when there is not is a lie you cannot recover from. Six boards make the ladder, from six characters and nothing but addition up to eight characters with all four operations, and the search grows from forty-five possible sentences to over seventeen thousand. There is a puzzle of the day, the same for everyone, and an unlimited random one whenever you want another. Shares are the grid of colours, never the answer.
How to play Equation Guess
- The answer is a true arithmetic sentence of a fixed length, with the result on its own after the equals sign.
- Every guess has to be a true sum too. The board will not take one that does not add up, so you cannot probe with nonsense.
- Green means that character is exactly where it belongs. Purple means it is in the sum but in a different place. Grey means it is not in the sum at all.
- Times and divide are worked out before plus and minus, the usual way. A division has to come out whole.
- Numbers are written without leading zeros, so 01+2=3 is not a legal sentence and never the answer.
- Repeats are counted properly. If the answer has one 4 and your guess has two, only one of them can come back coloured.
- The keypad remembers what you have learned: each character shows the best it has managed so far.
- Six guesses. The boards go from six characters with addition only up to eight characters with all four operations.
- Today’s puzzle is the same for everybody. Switch to a random one whenever you want another go.
- Beat a board to unlock the next. Progress is kept in your own browser.
Tips
- Open with something that spends a lot of different digits. A first guess that uses six distinct characters tells you far more than one that repeats.
- The equals sign is the cheapest thing to place. Once it is green you know how long each half is, and that cuts the field enormously.
- Think about the length of the answer rather than the digits in it. On an eight-character board a three-digit result forces a very different left-hand side from a one-digit one.
- Grey is information too. Ruling out four digits in one go is often worth more than getting one green.
- If a digit comes back purple in the same place twice, you have learned nothing new — move it somewhere you have not tried.
- On the longer boards, use your second guess to test operators rather than digits. Whether there is a times in there changes everything about the shape.
FAQ
Is Equation Guess free to play?
Yes. It runs in your browser with no download, no plugin, no sign-up and nothing to buy. There is a daily puzzle and unlimited random ones, and the first board is open straight away.
Why will it not take my guess?
Because a guess has to be a true sum of the right length. That is the rule that separates this from a word game — you cannot type a probe that means nothing, so every attempt is both a sentence and a question.
What do the colours mean?
Green is the right character in the right place. Purple is a character that is in the sum but somewhere else. Grey means it is not in the sum at all. The keypad shows the best each character has managed so far.
How are repeated digits handled?
Exactly as many as there really are. If the answer holds one 3 and you guess two, the better-placed one is coloured and the other comes back grey. Saying there is another 3 when there is not would be a lie you could not recover from, and it is the single most common bug in games like this.
Is 01+2=3 a valid answer?
No. Numbers are written without pointless leading zeros, so that sentence is not legal and will never be the answer. Nor is an operand of zero used on any board, because sums like 0×1000=0 are true and are not puzzles.
How do the boards get harder?
More characters and more operators, which means far more sentences to hide among — forty-five on the first board, over seventeen thousand on the last. Worth being honest about: a solver that can hold all seventeen thousand candidates in memory finds them in three or four guesses either way, so the ladder is the size of the search a person faces rather than something a machine can feel.
Is there a puzzle of the day?
Yes, and it is the same for everyone, changing at midnight UTC. There is also an unlimited mode for when you want another straight away. Sharing posts the grid of colours and never the answer.