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How to Videos Forum Rankings Books Print   Solution 9 Jul 2026
Easy:
4×4
5×5
Sudoku
Medium:
4×4
5×5
6×6
8×8
Killer
Sudoku
Difficult:
4×4
5×5
6×6
8×8
12×12
Extra
Difficult 8 × 8, Rating: ★★★★★      Solved 237 times
abcdefgh
1 
 
6
8
3
7+
 
20×
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2 
2 mod
 
3 mod
 
0 mod
42×
8
 
3 
 
2-
 
1-
 
 
4-
1 mod
4 
19+
 
 
18+
 
 
 
5 
 
 
 
3 mod
 
7-
16+
 
6 
1-
 
3-
 
1-
 
 
 
7 
6 mod
15+
 
 
 
3
4
2 mod
8 
 
 
 
1-
 
5 mod
 
 

Note: this puzzle also uses the modulo operator mod
a mod b = r means that when dividing a by b, the remainder is r. For example, 5 mod 2 = 1, and 3 mod 5 = 3.
Look here for a longer explanation.

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