A one-move Sudoku example
The answer is row 3, column 5: R3C5 must contain 6. Row 3 has three empty cells. Two are blocked by existing 6s, leaving just one place for the row’s missing 6. Here is the grid and the complete reasoning.
This is an original teaching example, not today’s Sudoku Sama puzzle or a puzzle from its Premium archive. It illustrates the app’s one-placement goal; this page is a static guide, not an online game.
Question: where does 6 go in row 3?
| Row / column | C1 | C2 | C3 | C4 | C5 | C6 |
|---|---|---|---|---|---|---|
| R1 | Empty | 2 | 3 | Empty | 5 | 6 |
| R2 | 4 | Empty | 6 | 1 | Empty | 3 |
| R3 | 2 | 3 | Empty | Empty | Empty | 1 |
| R4 | Empty | 6 | Empty | 2 | 3 | 4 |
| R5 | 3 | Empty | 5 | 6 | Empty | 2 |
| R6 | 6 | 1 | Empty | 3 | 4 | Empty |
The exclusion proof
- Start with the row. Row 3 reads 2, 3, empty, empty, empty, 1. It still needs 4, 5, and 6. The only possible positions for its 6 are C3, C4, and C5.
- Exclude C3. R2C3 already contains 6, so another 6 cannot go in column 3. Independently, R4C2 contains 6 in the same box as R3C3: rows 3–4, columns 1–3.
- Exclude C4. R5C4 already contains 6. Placing 6 at R3C4 would repeat it in column 4.
- Check C5. Its given column digits are 5, 3, and 4. Its box—rows 3–4, columns 4–6—contains 1, 2, 3, and 4. Neither group contains 6, and row 3 has no 6 yet.
Every completed row must contain 6 once. C3 and C4 are impossible, so R3C5 = 6. This is more than a number that fits: it is the only position left for 6 in that row. The conclusion follows from the givens without solving any other empty cell.
Use the same approach again
Focus on the requested digit rather than every missing number. Check each empty cell’s column and box, and name the clue that rules it out. If several positions survive, you need more reasoning—not a guess.
Classic Sudoku continues until every cell is filled. Sudoku Sama for iPhone and iPad instead asks for one placement. Review the 6×6 Sudoku rules or read how to play Sudoku Sama for the app’s controls.