Calcudoku: play free online
Calcudoku (KenKen): a Latin square whose cells are grouped into cages showing a result and an operation. Mental arithmetic and logic, with a single solution.
Play CalcudokuFree, zero ads, no sign-up, on mobile and desktop.
How to play
Each digit once per row and column. The digits in a cage give its result with its operation: sum, product, difference or quotient (two cells).
Example
Each digit once per row and column. The digits of a cage (thick border) give the written result with its operation: “8+” = sum 8, “2÷” = larger divided by smaller is 2.
Tips to get better
- Start with the one-cell cages (“=”): their digit is given.
- A two-cell “÷” cage with result 2 only takes double / half pairs (1-2, 2-4, 3-6).
- Products break down: a three-cell “60×” cage on a 5 × 5 grid can only be 3 × 4 × 5.
- Every row adds up to 1 + 2 + … + N: use it for the last cell of a “+” cage that spills over.
What this game trains
- Logical reasoning: deduce the solution from the rules, without guessing.
- Mental arithmetic: calculate in your head, fast and right.
Levels
Easy · Hard · Expert · Hardcore — each level has its own leaderboard.
Challenge your friends
At the end of a game, send your score as a link: your friend plays exactly the same puzzle and you compare your times. There is also a daily challenge and tournaments.