KenKen
- Category
- Brain
- Players
- 1
- Controls
- Tap
- Grid
- 4 x 4
- Loads
- Instant
Controls
| Tap a cell | Select it. |
| Tap a number | Place it. |
| Tap ✕ | Clear the cell. |
Next up
| Tap a cell | Select it. |
| Tap a number | Place it. |
| Tap ✕ | Clear the cell. |
KenKen, also sold as Calcudoku or MathDoku, puts arithmetic on top of a Latin square. Every row and column holds the numbers one to four exactly once, and the grid is divided into cages, each carrying a target and an operation that its numbers must produce.
It was devised by a Japanese maths teacher as a way of practising arithmetic without worksheets, and it works because the sums are never the hard part. Working out which combination fits both the cage and the Latin square constraint is where the puzzle actually lives.
Start with single-cell cages. A cage of one cell simply states its number outright, and each one immediately constrains its whole row and column.
Look for cages with only one combination. A two-cell cage totalling seven on a four grid must be three and four in some order, which fixes both cells to a pair even before you know which way round.
Use division and subtraction cages first. They are far more restrictive than addition, because only a handful of pairs divide evenly or differ by the right amount.
Remember the Latin square rule constrains the cage too. Two cells of a cage in the same row cannot hold the same number, which rules out combinations the arithmetic alone would allow.
A group of cells outlined together, with a target number and an operation its contents must produce.
Only if the cells are in different rows and columns, since the Latin square rule still applies.
Addition, subtraction, multiplication and division.
Yes, the puzzle goes by several names including Calcudoku and MathDoku.
No. KenKen runs entirely inside this page, so it starts the moment the page opens. There is nothing to download, no plugin, and no account to create.