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How to Videos Forum Timed Rankings Books PDF Print 16 Apr 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: ★★★★★  Points: 8     Solved 256 times
abcdefgh
1 
2
8+
5 mod
 
2-
 
4-
 
Clear cell
Bold cell
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2 
15+
 
3
30×
 
12+
 
8
3 
 
 
2
1-
 
 
1-
5 :
4 
 
5-
4
112×
 
10+
 
 
5 
2-
 
 
2-
 
 
7
6 
 
30×
 
 
1 mod
1 mod
 
7 
5 mod
 
56×
 
1 mod
 
0-
2 mod
8 
 
2
 
3
 
 
 
 

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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