solve

 sudoku

  to step 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
  <home


explanations:-
this is step 0


The Daily Telegraph rates this puzzle as a moderate level of dificulty.

The numbers given for this puzzle are in red.

Columns are c1 to c9
Rows r1 to r9
3x3 boxes 1 to 9

ie.the 3 in box1 is at c2r1

The rules -
Each column, row and 3x3 box must contain the numbers 1 to 9
It therefore follows that the cell where a row and a column cross must contain a number unique to that row and that column (and box).

See solution at step 23 to get the final picture of what we are trying to achieve.

c1
c2
c3
 
c4
c5
c6
 
c7
c8
c9
 
 
 
3
 
 
 
5
 
 
 
 
8
 
1
 
r1
box

1
2
&
3
 
box 1 
 
 
 
7
box 2 
6
 
 
 
box 3 
9
 
r2
 
4
 
 
 
 
 
 
 
 
 
 
r3
 
 
4
 
3
 
 
9
 
 
5
 
 
 
 
6
r4
box

4
5
&
6
 
box 4 
1
 
 
 
box 5 
 
 
 
box 6 
7
 
r5
 
6
 
 
 
 
8
 
 
1
 
 
9
 
3
 
r6
 
 
 
 
 
 
 
 
 
 
 
9
r7
box

7
8
&
9
 
box 7 
9
 
 
 
box 8 
8
 
6
 
 
box 9 
 
r8
 
 
6
 
1
 
 
 
 
2
 
 
 
8
 
r9



___________________________________

[ contact me, Roger Walker ]

15th january 2010 © 2012