Mathdoku
A KenKen puzzle: sudoku logic, with arithmetic instead of digits.
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How it plays
From 3×3 to 9×9
The start screen lists every cage size: 3×3, 4×4, 5×5, 6×6, 7×7, 8×8 and 9×9. Each puzzle uses only addition, subtraction, multiplication and division — nothing else.
No instructions, by design
The puzzles are offered without any instruction. There is no fixed starting place and no method of progression that can be learned as a strategy. Your brain is forced to dart between competing theories.
Trial and error is the method
KenKen™ was invented by the Japanese mathematics teacher Tetsuya Miyamoto, published in Japan by Gakken Co., Ltd. as Kashikoku naru Puzzle, and introduced to the western world by Robert Fuhrer of Nextoy and Dr. David Levy. KenKen™ is a trademark of Nextoy, LLC.
A quiet interface
Greyscale and whitespace are deliberate: nothing decorates the puzzle itself. When you are done you can share the result, print it on paper or switch the colour theme.
Screenshots
Screenshots
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About this game
Mathdoku
Mathdoku (also known as KenKen) replaces the digits of sudoku with arithmetic: every cage carries a target value and an operator, and you fill the cells with numbers so that no row or column repeats and every cage computes correctly.
It comes with no instructions on purpose, no fixed starting place and no strategy you can learn once and reuse. Your brain has to dart between competing theories — which is exactly why these puzzles work: it is impossible to solve them without the scientific process of trial and error.
KenKen™ was invented by the Japanese mathematics teacher Tetsuya Miyamoto, published in Japan by educational publisher Gakken Co., Ltd. as Kashikoku naru Puzzle, and introduced to the western world by toy inventor Robert Fuhrer, founder of Nextoy, and Chess Champion Dr. David Levy. KenKen™ is a trademark of Nextoy, LLC.
Pick a cage size to begin — starting at 3×3 is perfectly fine.
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Mathdoku
Sudoku with addition, subtraction, multiplication and division. Cage sizes from 3×3 to 9×9, no instructions and no strategy you can learn once.