Math Insight

The minimum number of clues (17) needed for a unique Sudoku was proved by exhaustive computer search in 2012.

Math Insight
✓ Completed! 👍
4
7
2
8
1
4
3
2
1
2
8
7
6
3
7
2
6
6
4
1
4
5
6
7
6
9
3
Pro Tip

Before using pencil marks, see how far you can get on a hard puzzle with pure mental tracking.

Pro Tip