YouPlay.com - your home for puzzles online
Puzzles for your publication or website. Free puzzles also availableVisit the Lovatts United Kingdom and Europe home pageVisit the Lovatts New Zealand home pageYou are visiting Lovatts Australasia - Australia and New Zealand

Killer Sudoku Video Tutorial

March 26, 2009 by Christine Lovatt  
Filed under Addoku Tutorials


Unique Blocks

Last modified on 2012-12-10 01:23:25 GMT. 1 comment. Top.

UNIQUE BLOCKS are essential tools for solving Kakuro and Killer Sudoku/Addoku puzzles. For example a total of 4 in 2 squares is a UNIQUE BLOCK. It can’t be 2 + 2 because each line of numbers can contain only one of each numeral. So the two squares can have only 1 or 3, though you don’t know in what order the 1 and 3 go until you look at the other sums around them.

This table gives you all the Unique blocks between 2 and 8 cells in length.

TOTAL
SQUARES
POSSIBLE NUMBERS
CAN’T HAVE
3
2
1,2
3,4,5,6,7,8,9
4
2
1,3
2,4,5,6,7,8,9
16
2
7,9
1,2,3,4,5,6,8
17
2
8,9
1,2,3,4,5,6,7
 
6
3
1,2,3
4,5,6,7,8,9
7
3
1,2,4
3,5,6,7,8,9
23
3
6,8,9
1,2,3,4,5,7
24
3
7,8,9
1,2,3,4,5,6
 
10
4
1,2,3,4
5,6,7,8,9
11
4
1,2,3,5
4,6,7,8,9
29
4
5,7,8,9
1,2,3,4,6
30
4
6,7,8,9
1,2,3,4,5
 
15
5
1,2,3,4,5
6,7,8,9
16
5
1,2,3,4,6
5,7,8,9
34
5
4,6,7,8,9
1,2,3,5
35
5
5,6,7,8,9
1,2,3,4
 
21
6
1,2,3,4,5,6
7,8,9
22
6
1,2,3,4,5,7
6,8,9
38
6
3,5,6,7,8,9
1,2,4
39
6
4,5,6,7,8,9
1,2,3
 
28
7
1,2,3,4,5,6,7
8,9
29
7
1,2,3,4,5,6,8
7,9
41
7
2,4,5,6,7,8,9
1,3
42
7
3,4,5,6,7,8,9
1,2
 
36
8
1,2,3,4,5,6,7,8
9
37
8
1,2,3,4,5,6,7,9
8
38
8
1,2,3,4,5,6,8,9
7
39
8
1,2,3,4,5,7,8,9
6
40
8
1,2,3,4,6,7,8,9
5
41
8
1,2,3,5,6,7,8,9
4
42
8
1,2,4,5,6,7,8,9
3
43
8
1,3,4,5,6,7,8,9
2
44
8
2,3,4,5,6,7,8,9
1

Download a printable PDF version