PlaySudoku.us
Hard · Puzzle #989
3
8
7
4
8
6
2
9
4
7
3
1
9
8
6
4
5
2
8
9
4
5
2
1
6
6
7
9
3
5
"Mathematics is the door and key to the sciences." — Roger Bacon
"Mathematics is the door and key to the sciences." — Roger Bacon
Scan by digit rather than by cell: find everywhere '7' must go before switching to '8'.
Scan by digit rather than by cell: find everywhere '7' must go before switching to '8'.