---
title: "Find the Mistake Level Up #13: 3 Sudoku Levels | Sudoku Flow"
description: "Three Sudoku boards, one wrong number in each: a 4×4, a 6×6, then a full 9×9. Level Up #13: play every level and see each answer."
url: https://sudokuflow.com/puzzles/level-up-13/
language: en
---
[Puzzles](https://sudokuflow.com/puzzles/) / Level Up #13
Level Up
# Level Up #13
Three boards, each with one wrong number, from a small 4×4 to a full 9×9. Play every level here, at your own pace.
[Watch on YouTube](https://youtube.com/shorts/OhfQTKjqwFI)
## Level 1 · 4×4
Tap the digit you think is wrong.
Level Up #13 · Level 1 · 4×4:
```text
2* . | 3* 1
4* . | 4 2
------+------
. . | 2 3
. 2* | 1* 4
```
Digits marked * were filled in by a player; the others were printed with the puzzle.
Show the answer
It's the blue 4 in row 2, column 1. Row 2 already has a printed 4 (row 2, column 3). A printed digit can't be wrong, so the blue one is. The right digit for that cell is 1.
## Level 2 · 6×6
Tap the digit you think is wrong.
Level Up #13 · Level 2 · 6×6:
```text
2 1* 6 | . 5 3
. 4* 3 | . 2 1*
---------+---------
. 5 1* | . 6* .
6 2 . | 5* . .
---------+---------
1* 6 5 | 3 4 2*
4* . 2 | 5 1* 6*
```
Digits marked * were filled in by a player; the others were printed with the puzzle.
Show the answer
It's the blue 5 in row 4, column 4. Column 4 already has a printed 5 (row 6, column 4). A printed digit can't be wrong, so the blue one is. The right digit for that cell is 1.
## Level 3 · 9×9
Tap the digit you think is wrong.
Level Up #13 · Level 3 · 9×9:
```text
4 . . | 5* 7* 1 | 3 . 2
. 5 . | . 2 4* | 9 . .
8* . . | 9* 3 6* | 1* 7 5
---------+----------+---------
6* 4 5 | 7 9* 3* | 2* . .
9 . . | . 1 8* | 5* 4 3
. . . | 4 5 2 | 6 9* .
---------+----------+---------
5 6 4 | 3 8* 7 | 1 2 9
2 . . | 1* 4 9* | 8* 5 6*
1 . . | 2* 6 5* | 7 3 4*
```
Digits marked * were filled in by a player; the others were printed with the puzzle.
Show the answer
It's the blue 1 in row 3, column 7. Column 7 already has a printed 1 (row 7, column 7). A printed digit can't be wrong, so the blue one is. The right digit for that cell is 4.
## 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.