How to Play Kakuro
Kakuro, also called cross sums, is a crossword made of numbers. Instead of words you write digits, and instead of definitions the clues are sums.
The grid
- White cells are where digits go.
- Black cells hold the clues. A black cell with a diagonal line can have two numbers: the one above the line is the sum of the white cells to its right, and the one below the line is the sum of the white cells below it.
- A run is a line of white cells, across or down, from one black cell to the next.
The rules
- Write a digit 1 to 9 in every white cell.
- The digits in each run add up to its clue.
- A digit can't repeat within a run.
That's all. Every kakuro on kawu has exactly one solution, and you can reach it by logic alone.
Combinations that only work one way
| Cells | Sum | Digits |
|---|---|---|
| 2 | 3 | 1 + 2 |
| 2 | 4 | 1 + 3 |
| 2 | 16 | 7 + 9 |
| 2 | 17 | 8 + 9 |
| 3 | 6 | 1 + 2 + 3 |
| 3 | 7 | 1 + 2 + 4 |
| 3 | 23 | 6 + 8 + 9 |
| 3 | 24 | 7 + 8 + 9 |
| 4 | 10 | 1 + 2 + 3 + 4 |
| 4 | 30 | 6 + 7 + 8 + 9 |
Where two such runs cross, the shared cell must hold a digit both allow. That's usually the first step.
On kawu
- Three sizes: 6×6, 8×8 and 9×9 white areas (plus the clue row and column).
- Notes, erase, undo and hints. "Show wrong digits" marks mistakes if you want it.
- The daily kakuro is the same for everyone.
Frequently asked questions
Can digits repeat in kakuro?
Not within a run. A digit can appear many times in the grid, but never twice in the same line of white cells across or down.
Is zero used in kakuro?
No. Only the digits 1 to 9 are used.
Last updated 2026-10-19