PlaySudoku.us
Expert · Puzzle #223
5
1
4
4
5
7
6
2
6
4
1
9
2
7
1
2
4
6
8
9
6
8
9
3
5
Competitive Sudoku solvers can hold the full pencil-mark state of a 9×9 grid in working memory, updating it mentally as they go.
Competitive Sudoku solvers can hold the full pencil-mark state of a 9×9 grid in working memory, updating it mentally as they go.
The puzzle was originally called "Number Place" in the US. The name "Sudoku" was given by Japanese publisher Nikoli.
The puzzle was originally called "Number Place" in the US. The name "Sudoku" was given by Japanese publisher Nikoli.