PlaySudoku.us
Hard · Puzzle #271
7
6
8
1
5
3
2
7
4
7
9
2
1
6
8
6
1
2
9
2
3
8
8
7
5
6
2
Track your error rate, not just your time. Accuracy improves faster than speed when you measure it.
Track your error rate, not just your time. Accuracy improves faster than speed when you measure it.
"It is not enough to have a good mind; the main thing is to use it well." — René Descartes
"It is not enough to have a good mind; the main thing is to use it well." — René Descartes