How to Play Kakuro
Kakuro is a logic-based number puzzle, sometimes called "Cross Sums." Think of it as a mathematical crossword!
The Basics
- The grid contains white cells (to fill) and black cells (clues)
- Fill the white cells with digits 1 through 9
- Each horizontal or vertical group of white cells is called a "run"
- The numbers in each run must add up to the clue
- No digit can repeat within the same run
Understanding Clue Cells
Clue cells have a diagonal line splitting them in two:
- Top-right number (17): The sum for the cells to the right of this clue
- Bottom-left number (23): The sum for the cells below this clue
Example
If a clue shows 16 for a run of 2 cells, the only solution is 7 + 9 (since 8 + 8 would repeat).
If a clue shows 10 for a run of 3 cells, possible combinations include:
- 1 + 2 + 7 = 10
- 1 + 3 + 6 = 10
- 1 + 4 + 5 = 10
- 2 + 3 + 5 = 10
Controls
Desktop
- Click to select a cell
- 1-9 to enter a number
- Delete to clear
- Arrow keys to navigate
- Tab to next empty cell
- N to toggle notes mode
- H to toggle helper panel
Mobile
- Tap a cell to select it
- Use the on-screen numpad to enter numbers
- Tap the backspace icon to clear
- Tap "Notes" to toggle pencil marks mode
Tips & Strategies
Start with runs that have only one possible combination (like 3 in 2 cells = 1+2, or 17 in 2 cells = 8+9).
Use pencil marks (notes mode) to track possible candidates for each cell.
Look for cells that belong to two runs - the answer must satisfy both clues.
Use the combination helper (press H) to see all valid digit combinations for any sum.
Enable "Show Errors" in settings if you want immediate feedback on mistakes.
Common Combinations
| Sum | 2 cells | 3 cells |
|---|---|---|
| 3 | 1+2 | - |
| 6 | 1+5, 2+4 | 1+2+3 |
| 16 | 7+9 | 1+6+9, 1+7+8, ... |
| 17 | 8+9 | 1+7+9, 2+6+9, ... |
| 24 | - | 7+8+9 |
Press H during gameplay to see all combinations