6×6 Calcudoku
A 6 × 6 grid with all four operations and bigger cages. Put 1 to 6 in every row and column so every cage hits its target.
How to play
- Fill the grid so every row and every column contains each number from 1 to 6 exactly once.
- The thick lines split the grid into cages. The small clue in the corner of each cage gives a target and an operation: the numbers in that cage must make the target using that operation.
- For − and ÷, start from the bigger number: a “2÷” cage could hold 3 and 6, in either order. A cage with no operation is just that number.
- Tap or click a square, then tap a number or type it. Turn on Notes to pencil in possibilities. Repeated numbers turn red, and so does a cage clue when its full cage misses the target.
What it practises
- Multiplication and division facts
- Factor pairs and prime factors
- Advanced logical reasoning
Level: Ages 10 and up
Tips for 6×6 Calcudoku
Break big multiplication clues into prime factors. “60×” in three squares could be 2, 5, 6 or 3, 4, 5, and a clue with a factor of 5 must include a 5.
Each row adds up to 21. Adding up the cages inside a row can reveal the one square left over.
Questions and answers
Is 6×6 Calcudoku hard?
It’s the hardest size here. There are more ways to make each target, so you’ll need notes and careful checking of rows and columns. Every puzzle still has exactly one solution.
What are notes?
Notes (or pencil marks) are small numbers you put in a square to remember what could go there. Turn on Notes, then tap numbers to add or remove them.
Is Calcudoku the same as KenKen?
They follow the same rules. KenKen® is a trademark of Nextoy, LLC; Calcudoku and MathDoku are the general names for this kind of puzzle.