booklet for kakuro and sudoku

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

THE RULES
Each row must contain each number from 1 to 9
Each column must contain each number from 1 to 9
Each box (small 3 by 3 grid shown by thicker lines) must contain each
number from 1 to 9
THIS MEANS THAT EACH NUMBER SHOULD ONLY APPEAR
ONCE IN EACH ROW, COLUMN AND BOX!
TOP TIPS FOR SOLVING SU DOKU
Pencil in ‘maybes’
In Su Doku you cannot guess! You must use logic to check all
possibilities and be certain before you enter a number. It can
help to put in little ‘maybe’ numbers in your grid whilst you check
all the possibilities.
15
Slicing and Dicing – Number Pairs
If you have a pair of numbers it can help find the third one.
In this example you can see there is a 1 in the middle row, a 1 in the
bottom row so we need to find a 1 in the top row. You know it cannot go in
the left box because it has a 1, it cannot go in the middle box because it
has a 1 so it must be in the right hand box in the top row. You have now
narrowed it down to two maybe positions shown by the arrows!
2
1
1
Now from your two maybe positions, you
can look down the columns for clues.
You can see there is a number 1 in this
column already.
This mean it must go in the left hand
maybe. So now you are certain
(remember no guessing!), you can rub out
your maybe numbers and put in your
bigger 1 in this box.
Once you have worked out the whole grid using this method, you can work
across and do the same thing. Slice across – Dice downwards!
Fill in the gaps
Remember the basic rule, each line must contain each number from 1 to 9.
If you have a line, column or box with only a few empty spaces you can put
in the numbers you are missing as maybe numbers and look for clues
around it.
Some Weblinks for Sudoku
A flash player to generate puzzles at ten levels of difficulties:
http://www.alcester.net/iwb/sudoku.html
A player to download to generate many puzzles to solve:
http://www.vnunet.com/articles/download/2149680
100 Sudoku puzzles to download and print:
http://www.vnunet.com/vnunet/downloads/2144124/100-sudoku-puzzles
An online games with easy, medium and hard puzzles:
http://www.jokefrog.com/games/sudoku.shtml
An online puzzle player
http://www.counton.org/sudoku/
Three puzzles to solve – different every day:
http://www.monterosa.co.uk/sudoku/
The Times Su Doku page:
http://www.timesonline.co.uk/section/0,,18209,00.html
Hot on the heels of Sudoku comes
Kakuro. Think of them as the
mathematical equivalent of
crosswords. They are also known as
Cross Sums or Kakro in Japan.
A Kakuro consists of a playing area of
filled and empty cells similar to a
crossword puzzle. Some black cells
contain a diagonal slash from top left
to bottom right with numbers in them,
called “the clues”. A number in the top
right corner relates to an “across” clue
and one in the bottom left a “down”
clue.
RULES
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
You must fill all the empty spaces with digits from 1 to 9.
The numbers must add up to the clue at the end of the row.
 Each number in a combination must be different.
Sound simple? Be warned it gets hard and is as addictive as Sudoku!!
TOP TIPS FOR SOLVING KAKURO
Kakuro is all about combinations. Which combination of
numbers can add up to your clue total. It is similar to Sudoku
as you cannot guess, you must use logic.
UNIQUE SETS
There are some totals which can only have one combination of numbers.
If you saw the sum
+
the boxes are (1 and 2).
If you saw the sum
+
and 7) or (3 and 6) or (4 and 5).
= 3, the only numbers which can go in
= 9, the answer could be (1 and 8) or (2
This means that a total of 3 with 2 boxes has a unique set of numbers. It
can only be one combination. A total of 9 with 2 boxes is not unique
because it has lots of answers.
Use your Kakuro helper sheet. It shows all the totals which are unique. A
good starting point is to look for totals which have a unique set of
numbers. If you look at the corners of the puzzle you will often find
these.
Look up the numbers in your table and find out the combinations for
these totals. You can now start to enter ‘maybe’ numbers just like
Sudoku.
3
12
12
COMBINATION CROSSINGS
This is known as cross sums because the combinations cross over each
other.
4
3
4
3
Look for a common number which is in both sets for
the number box where the combinations meet.
Number 1 is in both so that must be the number
where the lines cross.
1
4
3
3
If you look at this puzzle, you have:
 a clue total of 4 with two boxes
 a clue total of 3 with two boxes
From your unique sets you know that:
 3 must be 1 and 2
 4 must be 1 and 3
2
1
From this you can work out the
other numbers.
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
A total of 4 is 1 + 3
A total of 3 is 1 + 2
Once you fill in all your unique numbers it will give you lots of clues
for filling in the rest of the puzzle
MAXIMUM AND MINIMUM NUMBERS
If you look at this puzzle on the left there are two
totals.
19
When a total of 3 with 2 boxes you know it must be
1 and 2 so you can put in some maybes.
12
3
12
A total of 19 with 3 boxes is not unique but it can
help us decide which of our maybes is correct!
Here are the minimum and maximum totals you can have for each length.
Minimum
A length of
2
3
4
5
6
7
8
9
3 (1+2)
6 (1+2+3)
10 (1+2+3+4)
15 (1+2+3+4+5)
21 (1+2+3+4+5+6)
28 (1+2+3+4+5+6+7)
36 (1+2+3+4+5+6+7+8)
45 (1+2+3+4+5+6+7+8+9)
Maximum
17 (8+9)
24 (7+8+9)
30 (6+7+8+9)
35 (5+6+7+8+9)
39 (4+5+6+7+8+9)
42(3+4+5+6+7+8+9)
44 (2+3+4+5+6+7+8+9)
45 (1+2+3+4+5+6+7+8+9)
If you look at a length of 2 boxes the maximum
total is 17 made up of 8 and 9.
19
This can help you decide on our maybe 1 and 2
possibilities. This can get quite confusing though!
3
12
12
19
79
Look at this box. It can either be a 1 or a 2. If it
were 1, the other 2 boxes would need to total 18
because all three must total 19. We know that you
can not make a total of 18 with two boxes because
the maximum total you can have is 17. This means it
must be 2 in this box. You can then put in your
maybe possibilities for the other boxes.
79
3
1
2
THE MORE YOU PLAY KAKURO, THE EASIER IT
GETS! YOU WILL LEARN THE UNIQUE SETS
TO LOOK OUT FOR AND WORK OUT YOUR
OWN STRATEGIES.
2
3
4
5
6
7
3
4
16
17
6
7
23
24
10
11
29
30
15
16
34
35
21
22
38
39
28
29
41
42
12
13
79
89
123
124
689
789
1234
1235
5789
6789
12345
12346
46789
56789
123456
123457
356789
456789
1234567
1234568
2456789
3456789
Length
2
3
4
5
6
7
8
9
Smallest Largest
3
17
6
24
10
30
15
35
21
39
28
42
36
44
45
45
HUNGRY FOR MORE?
Lots of puzzles at different levels with tips for
beginners.
http://www.saidwhat.co.uk/sudokus/kakuro.php
Daily puzzle plus an archive of hundreds.
http://www.kakuro.info/
Puzzles to print or play online.
http://www.kakuro.net/
A brillinat site which includes a trial game player to
download.
http://www.kakuro.com/