Kakuro: sum 21 in 5 cells
A sum of 21 in 5 cells can be made 8 ways.
| Combination | Digit set |
|---|---|
| 1 + 2 + 3 + 6 + 9 | 12369 |
| 1 + 2 + 3 + 7 + 8 | 12378 |
| 1 + 2 + 4 + 5 + 9 | 12459 |
| 1 + 2 + 4 + 6 + 8 | 12468 |
| 1 + 2 + 5 + 6 + 7 | 12567 |
| 1 + 3 + 4 + 5 + 8 | 13458 |
| 1 + 3 + 4 + 6 + 7 | 13467 |
| 2 + 3 + 4 + 5 + 7 | 23457 |
What this tells you
- There are 8 possibilities, so this clue alone does not decide the digits. Use crossing runs and any known cells to eliminate combinations.
- Every digit from 1 to 9 appears in at least one combination, so there is nothing to exclude outright.
Related sums
The digits left out of each combination form a combination for the mirror run: sum 24 in 4 cells (page).