solve

 sudoku

   to step 0 1 2 3 4 5 6   <home
explanations:-
this is step:- 6


The 5 in c5 ripples through and makes 4 in c5r3; then 9 in c5r1; to 4 for c3r1; a 5 in c3r3; and 6 in c1r3. The new 5 in box 1 makes 9 in c3r8; 5 in c1r8; 9 is last in column 1; 2 is last in column 3

The 2 in c4r9 ripples through to 7 at c4r5; then 2 and 1 in r5; 5 and 7 are the only cells left in c4 and c5.

Job done? Well not quite. Now check each box, row and column for errors, ie two numbers the same.

However, errors tend to scream at you as you go along - if you get this far it should be correct.
c1
c2
c3
  
c4
c5
c6
  
c7
c8
c9
  
 
7
 
8
49 
4		  
 
1
49 
9
 
3		  
 
6
 
5
 
2
r1
 box

1
2
&
3
259 
9
box 1 
1
259 
2		  
579 
5
279 
7
 
6		  
 
3
box 3 
8
 
4
r2
56 
6
 
3
 45
5		  
 
8
45 
4
 
2		  
 
1
 
7
 
9
r3
 
4
 
5
 
7		  
 
6
 
3
 
9		  
 
2
 
1
 
8
r4
 box

4
5
&
6
 82
8
box 4 
9
 
3		  
27 
7
27 
2
17 
1		  
 
5
box 6 
4
 
6
r5
25 
2
 
6
 
1		  
 
4
25 
5
 
8		  
 
9
 
3
 
7
r6
 
3
 
2
 
8		  
 
9
17 
1
 
4		  
 
7
 
6
15
5
r7
 box

7
8
&
9
 59
5
box 7 
4
59 
9		  
 
3
12679 
6
17 
7		  
 
8
29 
2
 15
1
r8
 
1
 
7
269 
6		  
27 
2
 
8
 
5		  
 
4
 29
9
 
3
r9



___________________________________


15th january 2010 © 2014