---
title: "Naked Single: Sudoku Technique #3 | Sudoku Flow"
description: "Naked Single, explained step by step in a short video lesson. A cell with only one candidate left must hold that number."
url: https://sudokuflow.com/lessons/nakedSingle/
language: en
---

[Sudoku technique lessons](https://sudokuflow.com/lessons/) / Naked Single

Lesson 3

# Naked Single

## The rule

A cell with only one candidate left must hold that number.

## Step by step

1. Look at this row. It rules out 3, 4, 8 for this cell.
2. Now check this column. It also rules out 2, 7, 9.
3. The box also contains 1, 6, so remove those candidates from this cell.
4. All other candidates are eliminated! Only 5 can go in this cell.

[Read the full lesson, with more examples →](https://sudoku.rubigogames.com/techniques/naked-single.html) [Watch on YouTube](https://youtube.com/shorts/GqMipd_JeXI)

In our app, when this technique is the next step, the hint names it and shows you why, step by step. No ads, free to download.

[App Store iPhone, iPad, Mac](https://apps.apple.com/app/apple-store/id6502922368?pt=125379530&ct=sudokuflow_cta&mt=8) [Google Play Android](https://play.google.com/store/apps/details?id=com.rubigogames.sudoku&referrer=utm_source%3Dsudokuflow%26utm_medium%3Dcta%26utm_campaign%3Dlesson)

## Try it on more boards

Each board is a real puzzle from our app, at a moment where Naked Single applies. Find the step yourself, or tap Hint and the app's own hint walks you through it.

Naked Single practice board:

```text
. 8 . | 1 . . | 2 . .
4 . . | . 7 . | . 8 5
. . 6 | 9 . . | . . .
------+-------+------
. . . | 4 . 9 | 3 6 .
1 . . | . . . | . 5 .
7 . . | . 3 . | . . .
------+-------+------
. . . | . . . | . 4 1
3 . . | 6 . 1 | 5 . .
. 2 . | . 8 . | . 3 .
```

![Sudoku app icon](https://sudokuflow.com/assets/app-icon.png)

## Want more boards like this?

We also make a Sudoku app for iPhone, iPad, Mac and Android. There are no ads in it at all, it works offline, and when you ask for a hint it shows you the technique instead of just filling in a number.

[App Store iPhone, iPad, Mac](https://apps.apple.com/app/apple-store/id6502922368?pt=125379530&ct=sudokuflow_web&mt=8) [Google Play Android](https://play.google.com/store/apps/details?id=com.rubigogames.sudoku&referrer=utm_source%3Dsudokuflow%26utm_medium%3Dweb%26utm_campaign%3Dsite)

Sudoku Flow is made by Rubigo Games, the developer of the Sudoku app recommended on this site.