Naked Single: Step-by-Step Guide

Prerequisites

None. This is the first technique to master.

How to recognize it

• A cell’s candidate list narrows to a single number.
• Often follows easy eliminations from rows, columns, and boxes.

Why it works

In Sudoku each cell must contain a single digit 1–9 that does not repeat within its row, column, or 3×3 box. When all but one digit are eliminated, the remaining digit is logically forced.

Try it now

Interactive example coming soon: a mini-board that highlights a cell with exactly one candidate and explains the placement.

Practice puzzles

We will link daily puzzles that emphasize Naked Singles here.

Common pitfalls

• Confusing a single empty cell in a row with a Naked Single—verify the column and box too.
• Forgetting to update candidates after placing a digit.