Free Online Calcudoku
Solve arithmetic cages in a Latin-square grid — also known as KenKen or MathDoku. Each row and column must contain each digit once, and groups of cells (cages) must produce a target value using addition, subtraction, or multiplication. Easy, medium, and hard difficulty.
How to Play Calcudoku
- The grid is divided into outlined cages, each showing a target number and an operator (+, −, ×).
- Fill every cell with a digit so that each row and column contains each digit exactly once (Latin-square rule).
- The digits in each cage must produce the cage’s target value when the given operation is applied.
- For subtraction and division cages, digits can be arranged in any order within the cage.
- Click a cell, type a digit, and use Notes mode to pencil in candidates when unsure.
Difficulty Levels
- Easy — smaller grid; larger cages with simpler arithmetic. Ideal for newcomers to math puzzles.
- Medium — balanced cage sizes; requires combining Latin-square logic with arithmetic deduction.
- Hard — larger grid; small and complex cages demand careful candidate tracking.
Calcudoku Tips & Strategy
- Single-cell cages are free digits — fill them first.
- Start with cages that span a complete row or column; their digits must be all distinct values for that size.
- List all valid digit combinations for each cage, then eliminate options using the Latin-square rule.
- Focus on rows or columns where you have the most information to narrow down remaining candidates.
- Small subtraction cages (e.g. “1−” in a 2-cell cage) have very few valid combinations — use them as anchors.
Frequently Asked Questions
- What is the difference between Calcudoku and Sudoku?
- Calcudoku adds arithmetic cages on top of the Latin-square rule. There are no 3×3 box constraints, but cells must satisfy math targets.
- Is Calcudoku the same as KenKen?
- Yes — Calcudoku, KenKen, and MathDoku are all names for the same style of arithmetic grid puzzle.
- Is it free?
- Yes, completely free with no download or registration required.