Pointing candidates
A digit's candidates in a box all lie in one row or column. Remove that candidate from the rest of that row or column.
In box 5, 4 can go only in row 6, so it cannot go anywhere else in row 6. Remove candidate 4 from the rest of row 6.
What to look for
In one box, look for a digit whose two or three candidate positions all share a row or column. These are also known as pointing pairs or pointing triples.
Why it works
The box must contain the digit somewhere on that line. No cell on the same line outside the box can contain it as well.
Try it step by step
- Find every candidate position for a digit in one box.
- Check that all those positions share a row or column.
- Remove that candidate from the line outside the box.
Try it on a real puzzle
Start with the highlighted step, then keep solving. Use "Apply hint" to make the suggested change, or enter your own digits and candidate notes. Use "Undo" to reverse your last change.
| C1 | C2 | C3 | C4 | C5 | C6 | C7 | C8 | C9 | |
|---|---|---|---|---|---|---|---|---|---|
| R1 | |||||||||
| R2 | |||||||||
| R3 | |||||||||
| R4 | |||||||||
| R5 | |||||||||
| R6 | |||||||||
| R7 | |||||||||
| R8 | |||||||||
| R9 |
Use the arrow keys to move, 1-9 to enter a digit and Backspace or Delete to clear a cell. To add or remove a candidate, press C and then 1-9.
Source puzzle number: 230752 · Play this puzzle from the start
A simple example
If the only candidates for 7 in the top-left box are R1C1 and R1C2, remove candidate 7 from row 1 in columns 4-9.
A house is a row, column or 3 × 3 box. A line is a row or column. Two cells "see" each other when they share a house. R1C3 means row 1, column 3. Boxes are numbered 1-9 from left to right and top to bottom. Braces such as {1, 2} show a cell's candidates, not confirmed digits.