PlaySudoku.us
Hard · Puzzle #662
6
4
7
1
5
3
9
8
4
4
8
1
6
2
9
8
9
1
7
5
1
4
9
2
8
6
1
2
1
4
7
"The only way to learn mathematics is to do mathematics." — Paul Halmos
"The only way to learn mathematics is to do mathematics." — Paul Halmos
"Thinking is the talking of the soul with itself." — Plato
"Thinking is the talking of the soul with itself." — Plato