Naked pair
Two cells in the same house have the same two candidates. Remove those digits from the other cells in that house.
In row 3, the 2 highlighted cells can contain only the digits 1 and 6. These digits must fill those cells in some order, so remove these candidates from the other cells in row 3.
What to look for
Find two cells in one row, column or box that have exactly the same two candidates, such as {1, 2} and {1, 2}. The hints only point out naked pairs in rows and columns.
Why it works
The two cells must contain the two digits in some order. Neither digit can appear in another cell of the same house.
Try it step by step
- Find two cells with the same two candidates.
- Confirm that both cells belong to the same house.
- Remove both digits from every other cell in that house.
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: 243209 · Play this puzzle from the start
A simple example
If R1C1 and R1C2 both have only candidates {1, 2}, remove 1 and 2 from the other cells in row 1.
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.