Play Calcudoku Free Online

How to play Calcudoku (KenKen / Mathdoku)

Calcudoku — also known as KenKen or Mathdoku — is a Latin-square puzzle. Fill each row and column with the numbers 1 to N with no repeats, and make every bold cage reach its target using the shown operation (add, subtract, multiply or divide).

1. 1Fill rows and columns 1–N. Each row and column must contain the numbers 1 to N (grid size) with no repeats. There are no 3×3 boxes.
2. 2Reach each cage's target. The numbers in a bold cage must combine to its target using the shown operation: + sum, − difference, × product, ÷ quotient.
3. 3Single-cell cages are gifts. A one-cell cage shows its exact value — place it straight away.
4. 4Test combinations with Notes. Use Notes to pencil candidates, then cross them off using the Latin-square and cage rules together.
5. 5Solve fast for points. Finish quickly to earn a speed bonus and keep your daily streak alive.

Tips & strategy

Lock down the small cages first — a two-cell '÷' or '−' cage usually has only one or two valid pairs. Then use the no-repeat rule along each row and column to ripple those certainties outward. Multiplication cages with prime targets are especially constraining.