---
title: "Find the Mistake Level Up #4: 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 #4: play every level and see each answer."
url: https://sudokuflow.com/puzzles/level-up-4/
language: en
---
[Puzzles](https://sudokuflow.com/puzzles/) / Level Up #4
Level Up
# Level Up #4
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/XlaxhBe3E0g)
## Level 1 · 4×4
Tap the digit you think is wrong.
Level Up #4 · Level 1 · 4×4:
```text
2* . | 4 3
4* 3 | 2* 1
------+------
. . | . .
2 1* | 3 4*
```
Digits marked * were filled in by a player; the others were printed with the puzzle.
Show the answer
It's the blue 2 in row 1, column 1. Column 1 already has a printed 2 (row 4, column 1). 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 #4 · Level 2 · 6×6:
```text
3 . 1* | . 2 6*
6 4 2 | . 5 .
---------+---------
4 3* 5 | 2 6* 1*
2 1* 6* | 5* 3 4
---------+---------
. 2* 4* | 3 . 2
. . . | 6 4* .
```
Digits marked * were filled in by a player; the others were printed with the puzzle.
Show the answer
It's the blue 2 in row 5, column 2. Row 5 already has a printed 2 (row 5, column 6). A printed digit can't be wrong, so the blue one is. The right digit for that cell is 6.
## Level 3 · 9×9
Tap the digit you think is wrong.
Level Up #4 · Level 3 · 9×9:
```text
. . . | 8* 1 3* | 9 5* 6*
. . 3 | 9 6 5 | 2 4 7*
9 5* 6* | 2* 4* 7* | 1* 8 3
---------+----------+---------
. 2 . | 1 . 6 | . 3* 9
. . . | . 2* 9 | . 6 8*
. 6 9 | 4 . 8* | . 2 1
---------+----------+---------
. . . | 3* 9 4 | 6 1 5*
5 7* 4* | 6 7 1* | 8* 9 2
6 . 1 | . . 2 | 3 7* 4
```
Digits marked * were filled in by a player; the others were printed with the puzzle.
Show the answer
It's the blue 7 in row 8, column 2. Row 8 already has a printed 7 (row 8, column 5). A printed digit can't be wrong, so the blue one is. The right digit for that cell is 3.
## 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.