ShopUnique Blocks
UNIQUE BLOCKS are essential tools for solving Kakuro and 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
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SQUARES
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POSSIBLE NUMBERS
|
CAN’T HAVE
|
|
3
|
2
|
1,2
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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
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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
|
Yes a good table which should be memorised. I have been doing kakuro puzzles for over a year only paper based ones so no cheating getting the computer to give you help. I suppose the computers are useful to get you started as most of the books are much too hard initially even the best one i know gareth moore’s japanese puzzles or his essential book of kakuro.
I use a table like this but showing all combinations rather than just these start end numbers. for example for 2box numbers the number 5 to 15 contain more than one combination,eg 5 similarly for 3box numbers 8 to 22 and so on upto 7 box numbers.
It is as you have identified critical to know what numbers shouldn’t appear so we don’t make any silly mistakes or waste time trying to check down on a number which shouldn’t be considered.
Happy puzzling and have a prosperous new year,
Don’t forget to relax and take a break as it can become addictive.