Claiming
A row or column confines a candidate to one box.
Explanation
If all possible cells for a digit in a row or column fall inside one box, that box must host the digit on that line. Remove it from the other cells of the box.
Practice tip
Scan each row and column digit by digit, watching for candidates bunched in one box.
Example steps
- Find a row or column where one candidate only appears inside a single box.
- That box must host the digit on this line.
- Remove the candidate from the other cells of that box.