Kakuro Revisited

Naked Pairs and Triples in a Run

Two cells limited to the same two digits consume those digits, so no other cell of the run can use them.

Level 3 Subsets in a run Technique 08

1715101120191617103219201710119101912918398192127981929277913138
r9c5 and r9c6 can only hold 1 and 3. They use both digits, so r9c7 cannot be 1 or 3, and with the sum it must be 8.

placed key digits removed

Why it works

If two cells of a run can only hold 1 and 3 between them, then those two digits are used up. The rest of the run must be built from the other digits.

The same idea works for three cells and three digits. The catch is that the cells must be in the same run, or in runs that cannot both avoid the digits.

How to spot it

  1. Look for two cells in one run with exactly two candidates, and the same two candidates.
  2. Those two digits are locked in the pair.
  3. Remove both digits from every other empty cell of the run.
  4. Repeat with three cells and three digits.

Practice it

Open the app, choose a level that uses this technique, and ask the coach for the next step. Every hint links back to this guide.