Beginner technique
Naked Singles
Find cells where only one candidate remains after row, column, and box checks.
What it means
A Naked Single happens when a cell has only one possible value left. It is one of the cleanest Sudoku moves because the answer is forced by elimination, not by guessing.
How to use it
- Choose one empty cell.
- Remove numbers already seen in its row, column, and box.
- If one candidate remains, fill it confidently.