Kakuro: sum 21 in 3 cells
A sum of 21 in 3 cells can be made 3 ways.
| Combination | Digit set |
|---|---|
| 4 + 8 + 9 | 489 |
| 5 + 7 + 9 | 579 |
| 6 + 7 + 8 | 678 |
What this tells you
- There are 3 possibilities, so this clue alone does not decide the digits. Use crossing runs and any known cells to eliminate combinations.
- Digits that can never appear: 1, 2, 3. You can remove them from every cell of the run.
Related sums
The digits left out of each combination form a combination for the mirror run: sum 24 in 6 cells.