---
title: "Find the Mistake Level Up #19: 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 #19: play every level and see each answer."
url: https://sudokuflow.com/puzzles/level-up-19/
language: en
---
[Puzzles](https://sudokuflow.com/puzzles/) / Level Up #19
Level Up
# Level Up #19
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/dBlYiSnC5B4)
## Level 1 · 4×4
Tap the digit you think is wrong.
Level Up #19 · Level 1 · 4×4:
```text
. 3* | 4 .
2* 4 | 1* .
------+------
4 2 | 3 2*
3 1* | . .
```
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 3, column 4. Row 3 already has a printed 2 (row 3, column 2). 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 #19 · Level 2 · 6×6:
```text
3* 5* 1 | . 6 4*
. 6 2 | 5 . .
---------+---------
. 2* 6* | 1* . .
. 1* 4 | 6 3* 2
---------+---------
2 . 6 | 3 5 1
1* 3* 5 | . 2* 6
```
Digits marked * were filled in by a player; the others were printed with the puzzle.
Show the answer
It's the blue 6 in row 3, column 3. Column 3 already has a printed 6 (row 5, column 3). A printed digit can't be wrong, so the blue one is. The right digit for that cell is 3.
## Level 3 · 9×9
Tap the digit you think is wrong.
Level Up #19 · Level 3 · 9×9:
```text
1* 6* 5 | 9* 4* 7 | 8 3 2*
4* 7 . | 8* 3 2* | 1 . .
8* 3* 2 | 6 1 5 | 4* 7* 9
---------+----------+---------
6 . . | 7 . . | 5* 9 .
7* 9 8 | 4 5 6 | 3 2* 1*
5 . . | . . . | 6* . 7
---------+----------+---------
9* 5* . | . 7 . | 8* . .
3 8 6 | . 9 . | 7 . .
2* 4 7 | 5 6 8* | 9 1 3
```
Digits marked * were filled in by a player; the others were printed with the puzzle.
Show the answer
It's the blue 8 in row 7, column 7. Column 7 already has a printed 8 (row 1, column 7). A printed digit can't be wrong, so the blue one is. The right digit for that cell is 2.
## 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.