PlaySudoku.us
Hard · Puzzle #667
6
4
5
1
9
7
6
5
1
8
4
2
9
9
2
1
9
6
7
8
7
8
3
2
6
1
5
"There are no solved problems; there are only problems that are more or less solved." — Henri Poincaré
"There are no solved problems; there are only problems that are more or less solved." — Henri Poincaré
In 2005, Sudoku mania was so intense in the UK that it was credited with boosting pencil sales nationwide.
In 2005, Sudoku mania was so intense in the UK that it was credited with boosting pencil sales nationwide.