Naked Pair in Sudoku: Two Cells, Two Digits
When the singles run out, look for cells that work as a team. Two cells that share the same two candidates settle where those two digits go. Cells are named by row and column: r1c4 is row 1, column 4.
Step 1 of 4
Two cells, two digits
Look at row 1. The ringed cells, r1c4 and r1c7, have the same two candidates, 2 and 3, and nothing else. One of them is the 2 and the other the 3. You don't know which way round yet, but between them they take row 1's 2 and its 3.
That's a naked pair: two cells in one row, column or box with the same two candidates. No other cell in that row, column or box can hold either digit. Here r1c2 loses its 3.
Use the pair
You can rub the 3 out yourself. Turn on Notes mode, the ✎ lever after the 9, then select r1c2 and tap 3: with Notes mode on, a digit pencils in or rubs out a mark instead of going in the cell. Turn it off again to place a digit.
Then look down column 2. It still needs a 3, and before the pair there were two cells for it.
Your move
Use the pair, then place the digit it unlocks.
What the pair removes
Once the pair has done its work, what is left in r1c2?
Find the pair
Every empty cell has its candidates pencilled in, and none has just one. Look for two cells in one row, column or box with the same two candidates, then see where their digits can no longer go.
Your move
Find the naked pair that unlocks a digit, then place it.
What you learned
- A naked pair is two cells in one row, column or box with the same two candidates and no others.
- The pair's two digits leave every other cell of that row, column or box.
- The pair doesn't say which cell holds which digit. It says where the two digits can't go.
- Three cells in one row, column or box whose candidates are just three digits between them work the same way: a naked triple.
In this course
Unit 1The rules
Unit 2Solving techniques
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