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Page 1
Copyright © 2005 Crosswords Ltd
About guessing
Try not to. Until you have progressed to the tough and diabolical puzzles,
guessing is not only totally unnecessary, but will lead you up paths that can make
the puzzle virtually unsolvable. Simple logic is all that is required for gentle and
moderate puzzles.
Making a start
1
Logic will go a long way to solving
most sudokus. Ask yourself
questions like: ‘ifa 1 is in this box,
will it go in this column?’ or ‘ifa 9
is already in this row, can a 9 go
in this square?’
To make a start, look at each of
the boxes and see which squares
are empty, at the same time
checking that square’s column
and row for a missing number.
In this example, look at box 9.
There is no 8 in the box, but there
is an 8 in column 7 and in column
8. The only place for an 8 is in
column 9, and in this box the only
square available is in row 9. So
put an 8 in that square. You have
solved your first number.
What is sudoku?
You would imagine that with such a name this puzzle originated in Japan, but
it has been around for many years in the UK. However, the Japanese found an
example under the title ‘Number Place’ in an American magazine and translated
it as something quite different: su meaning number; doku which translates as
single or bachelor. It immediately caught on in Japan, where number puzzles
are much more prevalent than word puzzles. Crosswords don’t work well in the
Japanese language.
The sudoku puzzle reached craze status in Japan in 2004 and the craze spread
to the UK through the puzzle pages of national newspapers. The Daily Telegraph
uses the name Sudoku, but you may see it called su doku elsewhere. However,
there is no doubt that the word has been adopted into modern parlance, much
like ‘crossword’. Sudoku is not a mathematical or arithmetical puzzle. It works
just as well if the numbers are substituted with letters or some other symbols,
but numbers work best.
The challenge
Here is an unsolved sudoku
puzzle. It consists of a 9x9 grid
that has been subdivided into
9 smaller grids of 3x3 squares.
Each puzzle has a logical and
unique solution. To solve the
puzzle, each row, column and
box must contain each of the
numbers 1 to 9.
Throughout this document I refer
to the whole puzzle as the grid, a
small 3x3 grid as a boxand the
cell that contains the number as
a square.
Rows and columns are referred to with row number first, followed by the column
number: 4,5 is row 4, column 5; 2,8 is row 2, column 8. Boxes are numbered 1−9
in reading order, i.e. 123, 456, 789.
SOLVING SUDOKU
8 3 4
3
4 8 2 1
7
9 4
1
8 3
4 6
5
7 1
7
1 2 5 3
9
7 2 4
#5096
©
Crosswords Ltd, 2005
8 3 4
3
4 8 2 1
7
9 4
1
8 3
4 6
5
7 1
7
1 2 5 3
9
7 2 4
#5096
©
Crosswords Ltd, 2005
8
by Michael Mepham

Page 2
Copyright © 2005 Crosswords Ltd
8 3 4
3
4 8 2 1
7
9 4
1
8 3
4 6
5
7 1
7
1 2 5 3
9
7 2 4
#5096
©
Crosswords Ltd, 2005
8
8
8
2
8 3 4
3
4 8 2 1
7
9 4
1
8 3
4 6
5
7 1
7
1 2 5 3
9
7 2 4
#5096
©
Crosswords Ltd, 2005
8
8
8
2
4
4
8 3 4
3
4 8 2 1
7
9 4
1
8 3
4 6
5
7 1
7
1 2 5 3
9
7 2 4
#5096
©
Crosswords Ltd, 2005
8
8
8
2
24
2
4
8 3 4
3
4 8 2 1
7
9 4
1
8 3
4 6
5
7 1
7
1 2 5 3
9
7 2 4
#5096
©
Crosswords Ltd, 2005
8
8
8
2
Continuing to think about 8,
there is no 8 in box 1, but you
can see an 8 in rows 1 and 2.
So, in box 1, an 8 can only go in
row 3, but there are 2 squares
available. Make a note of this
by pencilling in a small 8 in both
squares. Later, when we have
found the position of the 8 in
boxes 4 or 7 we will be able to
disprove one of our 8s in box 1.
3
We were looking at box 9. As you
can see, there is a 2 in boxes 7
and 8, but none in box 9. The 2s
in row 8 and row 9 mean the only
place for a 2 in box 9 appears
to be in row 7, and as there is
already a 2 in column 8, there is
only one square left in that box
for a 2 to go. You can enter the 2
for box 9 at 7,7.
4
There is a similar situation with
the 4s in boxes 4 and 5, but here
the outcome is not so definite.
Together with the 4 in column
7 these 4s eliminate all the
available squares in box 6 apart
from two. Pencil a small 4 in
these two squares. Later on, one
or other of your pencil marks will
be proved or disproved.
5
Having proved the 2 in box 9
earlier, check to see if this helps
you to solve anything else. For
example, the 2 in box 3 shows
where the 2 should go in box 6:
it can only go in column 9, where
there are two available squares.
As we have not yet proved the
position of the 4, one of the
squares may be either a 4 or a 2.

Page 3
Copyright © 2005 Crosswords Ltd
The search for the lone number
InThe Daily TelegraphI call an easy sudoku puzzle ‘gentle’. This indicates a
level of complexity that can be tackled by beginners and casual sudoku solvers.
However, no matter what level of puzzle you are attempting, there are a few
strategies that will allow you to get to a solution more quickly.
The key strategy is to look for the
lone number. In this example, all
the options for box 5 have been
pencilled in. There appear to be
many places for the number 1 to
go, but look between the 8 and
3 − there is a lone number 1. It
was not otherwise obvious that
the only square for the number
1 was row 6, column 5, as there
is no number 1 in the immediate
vicinity. Checking the adjacent
boxes and relevant row and
column would not provide an
immediate answer either −but no
other number can go in that box.
While our example uses pencil
marks to illustrate the rule, more
experienced solvers are quite
capable of doing this in their
head.
Remember that this principal is
true for boxes, rows and columns:
if there is only one place for a
number to go, then it is true for
that box, and also the row and
column it is in. You can eliminate
all the other pencilled 1s in the
box, row and column.
6
Now solve a number on your
own. Look at box 8 and see
where the number 7 should go.
Continue to solve the more
obvious numbers. There will
come a point when you will
need to change your strategy.
What follows will provide you
with some schemes to solve the
complete sudoku.
If you’re getting the idea already and keen to get going, I’ve included the
sudoku below for you to attempt. You may find that you need some of the later
strategies to progress to a solution, but you can always return to it.
8 3 4
3
4 8 2 1
7
9 4
1
8 3
4 6
5
7 1
7
1 2 5 3
9
7 2 4
#5096
©
Crosswords Ltd, 2005
8
8
8
2
24
2
4
3 5
4 1
7
2
5
2
6
8 6
9 3
3
4
8
5 8
3 7
5
3
6
9
1
9 4
2 5
#5335
©
Crosswords Ltd
,2005
27
7
5
5
5
469 49
469
49
678
78
678
678
1
3 5
4 1
7
2
5
2
6
8 6
9 3
3
4
8
5 8
3 7
5
3
6
9
1
9 4
2 5
#5335
©
Crosswords Ltd
,2005
127
17
1
5
5
5
1469 149
1469
49
678
178
1678
1678
8 3 4
3
4 8 2 1
7
9 4
1
8 3
4 6
5
7 1
7
1 2 5 3
9
7 2 4
#5096
©
Crosswords Ltd, 2005

Page 4
Copyright © 2005 Crosswords Ltd
Triplets
In the previous example, our solver’s twins did just as well as a solved number
in helping to find her number. But if two unsolved squares can help you on your
way, three solvednumbers together certainly can.
Look at the sequence 2−8−1 in
row 8. It can help you solve the
7 in box 8. The 7s in columns 5
and 6 place the 7s in box 8 at
either 8,4 or 9,4. It is the 7 in row
7 that will provide sufficient clues
to make a choice. Because there
can be no more 7s in row 7, the
2−8−1 in row 8 forces the 7 in
box 7 to be in row 9. Although
you don’t know which square it
will be in, the unsolved trio will
prove that no more 7s will go in
row 9, putting our 7 in box 8 at
row 8. A solved row or column
of three squares in a box is good
news. Try the same trick with
the 3−8−6 in row 2 to see if this
triplet helps to solve any more.
Eliminate the extraneous
We have looked at the basic number-finding strategies, but what if these are
just not up to the job? Until now we have been casually pencilling in possible
numbers, but there are many puzzles that will require you to be totally
methodical in order to seek out and eliminate extraneous numbers.
If you have come to a point where obvious clues have dried up, before moving
into unknown territory and beginning bifurcation (more on that later), you should
ensure that you have actually found all the numbers you can. The first step
towards achieving this is to pencil in allpossible numbers in each square. It takes
less time than you’d think to rattle off ‘can 1 go’, ‘can 2 go’, ‘can 3 go’, etc., while
checking for these numbers in the square’s box, row and column.
Now you should look for matching pairsor trios of numbers in each column,
row and box. You’ve seen matching pairs before: two squares in the same row,
column or box that share a pair of numbers.
Twins
Why use one when two can do the job just as well? In sudoku we can easily
become blind to the obvious. You might look at a box and think there is no way
of proving a number because it could go in more than one square, but there are
times when the answer is staring you right in the face.
Take the sudoku opposite. It’s
an example of a gentle puzzle.
The solver has made a good
start at finding the more obvious
numbers, but having just solved
the 9 in box 4 she’s looking at the
9s in box 1. It seems impossible
to solve, with just a 9 in row 1
and another in column 2 that
immediately affect box 1.
But look more carefully and
you’ll see that the 9 in row 8
precludes any 9 in row 8 of box
7. In addition, the 9 in column 2
eliminates the square to the right
of the 4 in that box, leaving just
the two squares above and below
the 2 in box 7 available for the 9.
You’ve found a twin!
Pencil in these 9s. While you
don’t know which of these two
will end up as 9 in this box, what
you do know is that the 9 has
to be in column 3. Therefore a
9 cannot go in column 3 of box
1, leaving it the one available
square in column 1.
5
9
7 2
2 7
3 6
8
4
1
4 8
7
5
9
9 2
1
6
3
2 9
4 7
3 1
4
6
9
3
7
4
4
4
4
4
7
7
9
9
9
9
5
9
7 2
2 7
3 6
8
4
1
4 8
7
5
9
9 2
1
6
3
2 9
4 7
3 1
4
6
9
3
7
4
4
4
4
4
7
7
9
7
7
7
7
7
4 6
3 8 6
3
9 7
2
1
8 9
7
9
1
5
3 7
2
6
8 4
7
2 8 1
5 2

Page 5
Copyright © 2005 Crosswords Ltd
You can see what I mean in this
illustration. In this row at column
1 there is a 1 8 and at column 6
there is also a 1 8. This matching
pair is telling you that only either 1 or 8 is definitely at one or other of these
locations. If that is true then neither of these numbers can be at any other
location in that row.
So you can eliminate the 1 and
8 in any other square of the
row where they do not appear
together. As you can see, this
immediately solves the square at column 5 and then in column 7 the 9 is also
solved. This rule can be applied to a row, column or box.
The number-sharing rule can be taken a stage further. Say you have three
squares in a row that share the numbers 3, 7 and 9 and onlythose numbers.
They may look like 3 7, 3 9, 7 9 or 3 7, 3 9, 3 7 9 or even 3 7 9, 3 7 9, 3 7
9. In the same way as our pairs example worked, you can eliminate all other
occurrences of those numbers anywhere else on that row (or column or square).
It will probably take a minute or so to get your head round this one, but like the
pairs, where we were looking for two squares that held the same two numbers
exclusively, here we are looking for three squares that contain three numbers
exclusively.
Sometimes, the obvious simply needs to be stated, as in the case of two squares
that contain 3 7 and 3 7 9. If the 3 and the 7 occur onlyin those two squares
in a row, column or box, then either the 3 or 7 must be true in either one of the
squares. So why is the 9 still in that square with what is so obviously a matching
pair? Once that 9 has been eliminated, the pair matches and can now eliminate
other 3s and 7s in the row, column or box. You could say this was a ‘hidden’ pair.
You may find such hidden pairs in rows, columns or boxes, but when you find
one in a box, only when it has been converted to a true matching pair can you
treat it as part of a row or column. Hidden trios work in exactly the same way,
but are just more difficult to spot. Once you have assimilated the principle of
two numbers sharing two squares exclusively or three numbers sharing three
squares exclusively you will be well on the way to solving the most difficult
sudokus.
Stepping up the sudoku action
The strategies discussed so far will allow you to solve all but the most difficult
sudoku. However, when you come to the more testing grades of tough and
diabolical there are times when the logic required is much more difficult. What
happens in these puzzles is that you will reach a point where there are no
obvious numbers that can be solved. However, a few squares will have a choice
of two numbers. Obviously, one number in each of these pairs will be correct in
the final solution, but how do you find out which it is?
Let me say at this point that there isa logical and unique solution to each and
every one of the puzzles published in The Daily Telegraph. Just because there
are some computer programs that cry foul when they are incapable of solving
some sudokus, does not mean that youwill not be able to solve them with
patience and by the systematic elimination of alternatives. Hundreds (if not
thousands) of Daily Telegraphreaders, just ordinary, intelligent people, return
correct solutions to the most difficult sudokus published in the newspaper’s daily
competition.
So how do they do it? I’ll wager that when you started reading this you didn’t
think you’d be dealing with methodological analysis and bifurcation, but these
are the technical terms for the process of picking a likely pair of numbers,
choosing one and seeing where the number you have chosen gets you. Because
you can be confident that one of the numbers will eventually produce a route to
the solution, it is simply a matter of carefully analysing the options and testing
your choice. If your first choice doesn’t work out then you take the alternative
route.
In a tough puzzle, if you have solved everything you can and then made a
bifurcation, one or other of the pair will invariably provide a route through to
your solution. However, in a diabolical puzzle, neither of them may work and you
will have to move on to another pair and make another bifurcation.
The next stage
The sudoku puzzles published by The Daily Telegraph are graded by level of
difficulty: gentle and moderate require straightforward logic, and have no
apparent dead or loose ends. However, the tough and diabolical puzzles will
present something of a challenge and require some heavy pencil-work before
numbers can finally be resolved.
If you think of a sudoku puzzle as a maze, gentle and moderate puzzles are
labyrinths with a simple path straight through to the exit. Tough and diabolical
puzzles have dead-end paths which force you to try different routes. A tough
puzzle may only have one of these dead ends to cope with, or it may be
particularly tortuous. Diabolical puzzles will have at least one, and maybe more
paths to follow, before finding the correct solution. The way to navigate this
maze can be found in classical mythology, so allow me to tell you a story.

Page 6
Copyright © 2005 Crosswords Ltd
Ariadne’s thread
As well as creating sudoku puzzles, I also compile the giant general knowledge
crossword for The Daily TelegraphWeekend supplement, so excuse me if I put
that hat on for a few moments to remind you briefly of the story of Ariadne’s
thread.
Ariadne was the daughter of King Minos of Crete, who conquered the Athenian
nation. An unfortunate intimacy between Ariadne’s mother and a bull resulted
in the birth of the monster −half-bull, half-man −called the Minotaur, who was
banished to spend his days in the Labyrinth. King Minos, being something of a
tyrant, called for tribute from Athens in the form of young men and women to be
sacrificed to the Minotaur.
The young Athenian hero, Theseus, offered to accompany a group of the young
unfortunates into the Labyrinth so that he could kill the Minotaur and save
Athens from the cruel tribute. Ariadne fell in love with Theseus and, not wishing
to see him lost in the Labyrinth once he had dealt with her bovine half-brother,
she provided him with a means of escape −a silken thread. Theseus had simply
to unwind it while he went through the Labyrinth; should he come to a dead end
he could rewind it to the point where he had made a choice of paths and continue
his search using the alternative route. The scheme worked out beautifully, the
Minotaur was slain, Theseus found his way back out of the Labyrinth and Ariadne
. . . well, she got her ball of string back, no doubt.
Replacing my sudoku hat, I hope that this tale of Ariadne’s thread has served to
illustrate the method used to solve tough and diabolical sudokus. Take a look at
the following illustration that represents a gentle or moderate sudoku.
Your labyrinth has been straightened out in the diagram. It may not feel like it at
the time, but there’s just a start and finish.
Tough sudokus
In tough and diabolical sudokus too there is a beginning and an end to the maze.
But now the illustration is slightly more complicated:
Somewhere along your route you will find that none of your pencilled numbers
provide a next step. You may look at a square at a1where there are two options.
One of the options takes you up a blind alley at a2and you must rewind your
‘thread’ to a1and choose the other number that takes you to a solution.
There may be another pair at b1that you could have chosen. One of the choices
would have been wrong and led you to point b2, but the other would have been
correct. Although the route is different, you end up with a solution.
However, if you had chosen either of the third pair at c1, neither number would
have provided sufficient clues to get to the end.
At a dead end you may be presented with numerous choices of pairs. Although
one or other of each of these pairs will be correct in the final solution, there is no
guarantee that it will provide sufficient clues to take you through to the end of
the puzzle.
Luckily in a 9×9 tough sudoku there are not too many options that don’t provide
sufficient clues, so the chances are that your first or second choice will get you
on the right track.
a1
a2
b1
b2
c1

Page 7
Copyright © 2005 Crosswords Ltd
Looking at a diabolical puzzle
In its structure there is little difference between a tough sudoku and a diabolical
puzzle. The difference is that there are more places where clues can run out and
more dead ends.
Take the example illustrated
here: you can see the squares
our solver has managed to
complete using the strategies we
have discussed previously. For
clarity’s sake we’ll ignore all the
‘pencil’ marks on the grid except
for the first pair: at 1,5 we have
either a 6 or a 9. This would be
the equivalent to point a1, b1or c1
on our tough sudoku illustration.
There is at least one other pair
our solver could have chosen on
the grid, but this was the first, so
let’s be logical and use that.
Our solver chooses to try the 6
first, and the following diagram
shows the numbers she is able to
complete using this number.
But with just two squares to fill,
look at what we have: at 4,8 the
box needs a 4 to complete it, but
there is already a 4 in that row
at 4,6. Similarly, at 5,4 that box
needs a 6, but one already exists
in that row at 5,7. No second
guess was needed to prove that
at 1,5 the 6 was incorrect.
So our solver returns to 1,5 and
tries the 9. Now we are able to
prove the 9 at 2,1, but nothing
else is obvious; every square is
left with options. In this case we
could leave both 9s, because we
proved without doubt that the
6 at 1,5 could not be correct,
but if the 6 had simply left us
without sufficient clues, as the
9 did, we wouldn’t know which
was true. So, rather than start a
new, uncertain path it is better to
return to the situation we were in
before we chose at 1,5 and find
another square to try from. This
is a base we know to be true.
In this illustration we can see that
our solver next looks at square
1,7 where the choice is between
a 3 and a 6. Choosing the 3 she
finds herself on a path that takes
her to just two more to go . . .
Whoops. We need a 2 to
complete box 7, but there’s
already a 2 in that row at 9,5. In
box 9 we need an 8, but there’s
an 8 in row 8 already. It has
happened again!
1
7
4
5
1
3 2 4
8
9 8
5
1
8
5
9
4
5
3 2
7
3 1 8
6
5
6
1
3
8
69
5
4
2
1
8
7
8
1
9
1
6
9 2
4
5
4
9
3
4
5
9
1
9
5 6 7
3
7
9
6
9
6
3
2
7
2
3
2 4
7
6 3
8
6
2
2
7
7
8
1
7
4
5
1
3 2 4
8
9 8
5
1
8
5
9
4
5
3 2
7
3 1 8
6
5
6
1
3
8
69
5
4
2
1
8
7
8
1
9
1
6
9 2
4
5
4
9
3
4
5
9
1
9
5
9
9
1
7
4
5
1
3 2 4
8
9 8
5
1
8
5
9
4
5
3 2
7
3 1 8
6
5
6
1
3
8
36
5
4
2
1
8
7
8
1
9
1
6
9 2
4
5
4
9
3
4
5
9
1
9
5
6
7
3
7
9
6
9
6
3
2
7
2
4
2
4
6
6
3
7
6
2
3
7
7
8
1
7
4
5
1
3 2 4
8
9 8
5
1
8
5
9
4
5
3 2
7
3 1 8
6
5
6
1
3
8
69
5
4
2
1
8
7
8
1
9
1
6
9 2
4
5
4
9
3
4
5
9
1
5
9

Page 8
Copyright © 2005 Crosswords Ltd
At this point, I find a couple of
slugs of scotch help.
If you still have the time or
inclination, wind in the thread to
get back to 1,7. 3 was chosen
last time. Try 6.
I’ll let you finish up. I’m off down
the pub!
Truly diabolical sudokus
Up to now I’ve been kind to you. If there have been pairs of numbers giving you
a choice of routes, one or other of your choices has led to the end of the puzzle.
But what if there are only one or two squares that present a choice. Having used
all the techniques we have talked about none of the clues provide a clear route
through to the end? This is where you face really diabolical sudokus.
The next diagram illustrates just what can happen, only occasionally, in a
diabolical sudoku. But at least you’ll know the worst.
Having arrived at our first dead end −a −we go for one of the numbers and take
it through to the point where this route also comes to a choice −b. If the path is
clear, i.e., we are not in a situation where we would have two of the same number
in a box, row or column, we now have to take another leap into the unknown and
select one of a second pair. If this path comes to a dead end, let’s rewind to point
c
a
b
Now try some examples...
1
7
4
5
1
3 2 4
8
9 8
5
1
8
5
9
4
5
3 2
7
3 1 8
6
5
6
1
3
8
36
5
4
2
1
8
7
8
1
9
1
6
9 2
4
5
4
9
3
4
5
9
1
9
5
6
band try the other number. We can see that it is going to be a dead end in the
diagram. Having found no way forward on either of these paths we rewind our
silken thread to take us back to point a. Here we choose the other number at this
square. This takes us to c, where we have to choose again. If our luck changes we
find a route through to the end, otherwise we have to try the other number at c
before we find our path clear.
Of course I have only illustrated part of the full diabolical sudoku map here, and
there may be other choices like the one at point awith equally difficult routes to
follow.
If this scares your pants off, don’t worry too much. I’ve shown a worst-case
scenario and most diabolical sudokus can be tackled just like tough puzzles: if you
come to an impasse, simply pick another pair. It’s only when you have just one or
two options that you’ll find yourself in the pickle I’ve illustrated.
The last word
Every day I receive a few emails from Daily Telegraphsolvers who tell me how
they struggled on Tuesday’s moderate puzzle, but flew through the diabolical
example on Friday. My answer is always that my grading of puzzles is subjective.
I have no way of knowing what mistakes a solver might make, how experienced
he or she is or whether he or she is suffering from a bad day or not. The same
puzzle may take one person 30 minutes and another two hours, and it’s not
always down to the level of experience of the solver. Also, some people have an
innate ability to spot the clues. With practice, others develop this ability without
realising it.
No matter how good or bad you are at sudoku, what I can guarantee is that these
puzzles will give you a good mental workout. As keep fit for the brain, in my
experience as a puzzle setter, sudoku is as good as it gets. Have fun.
Acknowlegements
Firstly, may I thank the thousands of Daily Telegraphreaders who have
contacted me since the puzzle first appeared. Their suggestions and unbounded
enthusiasm for sudoku is reflected in the size of my daily postbag. Many of
their comments, questions and suggestions have helped to shape this tutorial.
Specifically I’d like to thank John MacLeod whose contribution on extraneous
numbers arrived on my desk just as I was about to tackle the subject with a
heavy cold — what luck — and Phillip Rowe for his help in grading puzzles.

Page 9
Copyright © 2005 Crosswords Ltd
6 2
1
8
7 1
1 7
3 2
7
3
4
5
8
8
4
7
4 6
5 8
1 7
4
4
6 5
#5329
©
Crosswords Ltd, 2005
1
4 2
5
2
7 1
3 9
4
2
7 1
6
4
6
7 4
3
7
1 2
7 3
5
3
8 2
7
#5232
©
Crosswords Ltd, 2005
1 9
8
6
8 5
3
7
6
1
3 4
9
5
4
1
4 2
5
7
9
1
8 4
7
7
9 2
9
7
8 6
3 1
5
2
8
6
7
5
6
3
7
5
1
7
1
9
2
6
3 5
5 4
8
7
TOUGH
Should give an experienced
solver some entertainment.
MODERATE
Will require some skill and
practice.
GENTLE
Easily solved with simple
logic. The difference between
these and Moderate puzzles
may sometimes seem
marginal. Ratings must be
subjective, as there is no way
of knowing the skill level of
the solver.
DIABOLICAL
Be prepared for multiple
seeming dead ends that
require extreme logic or
intelligent guessing. This
example is as hard as you will
ever get.
Sample Sudoku

Page 10
Copyright © 2005 Crosswords Ltd
7 3 6 2 9 1 4 5 8
8 4 2 6 5 3 9 7 1
5 9 1 7 8 4 6 3 2
9 1 7 5 3 8 2 4 6
2 5 4 9 6 7 1 8 3
6 8 3 1 4 2 7 9 5
4 6 9 3 1 5 8 2 7
1 7 5 8 2 9 3 6 4
3 2 8 4 7 6 5 1 9
8 1 3 4 2 9 7 6 5
4 6 2 5 7 1 8 3 9
7 9 5 3 6 8 1 4 2
2 4 7 1 5 3 9 8 6
5 3 9 8 4 6 2 1 7
6 8 1 2 9 7 4 5 3
9 7 8 6 1 5 3 2 4
1 2 6 7 3 4 5 9 8
3 5 4 9 8 2 6 7 1
3 4 1 9 2 7 5 6 8
6 9 2 1 8 5 7 3 4
8 5 7 4 6 3 1 9 2
1 3 4 2 9 6 8 7 5
2 7 8 5 3 4 6 1 9
5 6 9 7 1 8 4 2 3
4 2 5 3 7 1 9 8 6
9 1 6 8 4 2 3 5 7
7 8 3 6 5 9 2 4 1
2 9 5 7 4 3 8 6 1
4 3 1 8 6 5 9 2 7
8 7 6 1 9 2 5 4 3
3 8 7 4 5 9 2 1 6
6 1 2 3 8 7 4 9 5
5 4 9 2 1 6 7 3 8
7 6 3 5 2 4 1 8 9
9 2 8 6 7 1 3 5 4
1 5 4 9 3 8 6 7 2
TOUGH
MODERATE
GENTLE
DIABOLICAL
Solutions

Page 11
Copyright © 2005 Crosswords Ltd
sudoku worksheet
sudoku worksheet