Combination Elimination
Medium
Used by Smart Hint
A digit that appears in none of this run's remaining sum combinations can be ruled out of every cell in it.
- Cells that establish the pattern
- Digit ruled out
How it works
- Two cells sum to 7: the combinations are 1+6, 2+5, and 3+4.
- No combination contains a 7, 8, or 9 — whatever crossing runs might otherwise allow.
- Strike every digit that appears in none of the run's combinations.