PlaySudoku.us
Easy · Puzzle #645
4
7
1
9
5
8
6
3
5
6
2
3
8
1
8
9
3
2
3
1
4
7
3
6
8
5
5
3
2
1
6
2
6
7
1
9
8
8
7
4
5
3
4
9
7
The hardest Sudoku puzzles require techniques equivalent to propositional logic — the same foundation used in computer proofs.
The hardest Sudoku puzzles require techniques equivalent to propositional logic — the same foundation used in computer proofs.
Solve three Medium puzzles in a row without making a single mistake. Accuracy over speed.
Solve three Medium puzzles in a row without making a single mistake. Accuracy over speed.