Step 0

Starting puzzle

1 2 3 4 5 6 7 8 9
A 7   2 3     1    
B         8        
C 5     2     8 4  
D       7       2  
E     1       3    
F   6       8      
G   1 9     4     2
H         9        
I     8     1 4   3

Step 1

The number 2 does not yet appear in row B. Due to other 2s on the grid, the only place it can go is cell B7.

1 2 3 4 5 6 7 8 9
A 7   2 3     1    
B         8   2    
C 5     2     8 4  
D       7       2  
E     1       3    
F   6       8      
G   1 9     4     2
H         9        
I     8     1 4   3

Step 2

The number 8 does not yet appear in row A. Due to other 8s on the grid, the only place it can go is cell A2.

1 2 3 4 5 6 7 8 9
A 7 8 2 3     1    
B         8   2    
C 5     2     8 4  
D       7       2  
E     1       3    
F   6       8      
G   1 9     4     2
H         9        
I     8     1 4   3

Step 3

The number 9 does not yet appear in row I. Due to other 9s on the grid, the only place it can go is cell I8.

1 2 3 4 5 6 7 8 9
A 7 8 2 3     1    
B         8   2    
C 5     2     8 4  
D       7       2  
E     1       3    
F   6       8      
G   1 9     4     2
H         9        
I     8     1 4 9 3

Step 4

The number 1 does not yet appear in column 1. Due to other 1s on the grid, the only place it can go is cell B1.

1 2 3 4 5 6 7 8 9
A 7 8 2 3     1    
B 1       8   2    
C 5     2     8 4  
D       7       2  
E     1       3    
F   6       8      
G   1 9     4     2
H         9        
I     8     1 4 9 3

Step 5

Because of the number 1 just placed, the only position in row C for another 1 is cell C5.

1 2 3 4 5 6 7 8 9
A 7 8 2 3     1    
B 1       8   2    
C 5     2 1   8 4  
D       7       2  
E     1       3    
F   6       8      
G   1 9     4     2
H         9        
I     8     1 4 9 3

Step 6

Because of the number 1 just placed, the only position in column 4 for another 1 is cell F4.

1 2 3 4 5 6 7 8 9
A 7 8 2 3     1    
B 1       8   2    
C 5     2 1   8 4  
D       7       2  
E     1       3    
F   6   1   8      
G   1 9     4     2
H         9        
I     8     1 4 9 3

Step 7

Because of the number 1 just placed, the only position in row D for another 1 is cell D9.

1 2 3 4 5 6 7 8 9
A 7 8 2 3     1    
B 1       8   2    
C 5     2 1   8 4  
D       7       2 1
E     1       3    
F   6   1   8      
G   1 9     4     2
H         9        
I     8     1 4 9 3

Step 8

Because of the number 1 just placed, the only position in column 8 for another 1 is cell H8.

1 2 3 4 5 6 7 8 9
A 7 8 2 3     1    
B 1       8   2    
C 5     2 1   8 4  
D       7       2 1
E     1       3    
F   6   1   8      
G   1 9     4     2
H         9     1  
I     8     1 4 9 3

Step 9

The number 3 does not yet appear in column 8. Due to other 3s on the grid, the only place it can go is cell B8.

1 2 3 4 5 6 7 8 9
A 7 8 2 3     1    
B 1       8   2 3  
C 5     2 1   8 4  
D       7       2 1
E     1       3    
F   6   1   8      
G   1 9     4     2
H         9     1  
I     8     1 4 9 3

Step 10

The number 4 is missing from row A and its only possible position is cell A5.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1    
B 1       8   2 3  
C 5     2 1   8 4  
D       7       2 1
E     1       3    
F   6   1   8      
G   1 9     4     2
H         9     1  
I     8     1 4 9 3

Step 11

Because of the number 4 just placed, the only position in column 4 for another 4 is cell E4.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1    
B 1       8   2 3  
C 5     2 1   8 4  
D       7       2 1
E     1 4     3    
F   6   1   8      
G   1 9     4     2
H         9     1  
I     8     1 4 9 3

Step 12

The number 4 does not yet appear in column 9. Due to other 4s on the grid, the only place it can go is cell F9.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1    
B 1       8   2 3  
C 5     2 1   8 4  
D       7       2 1
E     1 4     3    
F   6   1   8     4
G   1 9     4     2
H         9     1  
I     8     1 4 9 3

Step 13

The number 9 is missing from column 4 and its only possible position is cell B4.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1    
B 1     9 8   2 3  
C 5     2 1   8 4  
D       7       2 1
E     1 4     3    
F   6   1   8     4
G   1 9     4     2
H         9     1  
I     8     1 4 9 3

Step 14

The number 9 is missing from row A and its only possible position is cell A9.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1     9 8   2 3  
C 5     2 1   8 4  
D       7       2 1
E     1 4     3    
F   6   1   8     4
G   1 9     4     2
H         9     1  
I     8     1 4 9 3

Step 15

Because of the number 9 just placed, the only position in row C for another 9 is cell C2.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1     9 8   2 3  
C 5 9   2 1   8 4  
D       7       2 1
E     1 4     3    
F   6   1   8     4
G   1 9     4     2
H         9     1  
I     8     1 4 9 3

Step 16

The number 3 does not yet appear in row C. Due to other 3s on the grid, the only place it can go is cell C3.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1     9 8   2 3  
C 5 9 3 2 1   8 4  
D       7       2 1
E     1 4     3    
F   6   1   8     4
G   1 9     4     2
H         9     1  
I     8     1 4 9 3

Step 17

The number 6 is missing from box A1-C3 and its only possible position is cell B3.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1   6 9 8   2 3  
C 5 9 3 2 1   8 4  
D       7       2 1
E     1 4     3    
F   6   1   8     4
G   1 9     4     2
H         9     1  
I     8     1 4 9 3

Step 18

B2 is the last empty cell in box A1-C3 and the missing number is 4.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D       7       2 1
E     1 4     3    
F   6   1   8     4
G   1 9     4     2
H         9     1  
I     8     1 4 9 3

Step 19

The number 8 is missing from row D and its only possible position is cell D1.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8     7       2 1
E     1 4     3    
F   6   1   8     4
G   1 9     4     2
H         9     1  
I     8     1 4 9 3

Step 20

The number 4 does not yet appear in row D. Due to other 4s on the grid, the only place it can go is cell D3.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8   4 7       2 1
E     1 4     3    
F   6   1   8     4
G   1 9     4     2
H         9     1  
I     8     1 4 9 3

Step 21

Because of the number 4 just placed, the only position in column 1 for another 4 is cell H1.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8   4 7       2 1
E     1 4     3    
F   6   1   8     4
G   1 9     4     2
H 4       9     1  
I     8     1 4 9 3

Step 22

In box A4-C6, the missing 5 can only go in cell A6 or B6. All of these cells are in column 6. Therefore 5 can be eliminated from other cells in column 6 including D6, E6, H6. The remaining possibilities are marked with small numbers.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8   4 7   369   2 1
E     1 4   269 3    
F   6   1   8     4
G   1 9     4     2
H 4       9 2367   1  
I     8     1 4 9 3

Step 23

In box A4-C6, the missing 6 can only go in cell A6 or C6. All of these cells are in column 6. Therefore 6 can be eliminated from other cells in column 6 including D6, E6, H6. The remaining possibilities are marked with small numbers.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8   4 7   39   2 1
E     1 4   29 3    
F   6   1   8     4
G   1 9     4     2
H 4       9 237   1  
I     8     1 4 9 3

Step 24

In box A4-C6, the missing 7 can only go in cell B6 or C6. All of these cells are in column 6. Therefore 7 can be eliminated from other cells in column 6 including H6. The remaining possibilities are marked with small numbers.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8   4 7   39   2 1
E     1 4   29 3    
F   6   1   8     4
G   1 9     4     2
H 4       9 23   1  
I     8     1 4 9 3

Step 25

In box A7-C9, the missing 7 can only go in cell B9 or C9. All of these cells are in column 9. Therefore 7 can be eliminated from other cells in column 9 including E9, H9. The remaining possibilities are marked with small numbers.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8   4 7   39   2 1
E     1 4   29 3   568
F   6   1   8     4
G   1 9     4     2
H 4       9 23   1 568
I     8     1 4 9 3

Step 26

In column 4, the missing 5 can only go in cell G4 or H4 or I4. All of these cells are in box G4-I6. Therefore 5 can be eliminated from other cells in box G4-I6 including G5, I5. The remaining possibilities are marked with small numbers.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8   4 7   39   2 1
E     1 4   29 3   568
F   6   1   8     4
G   1 9   367 4     2
H 4       9 23   1 568
I     8   267 1 4 9 3

Step 27

In column 4, the missing 6 can only go in cell G4 or H4 or I4. All of these cells are in box G4-I6. Therefore 6 can be eliminated from other cells in box G4-I6 including G5, I5. The remaining possibilities are marked with small numbers.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8   4 7   39   2 1
E     1 4   29 3   568
F   6   1   8     4
G   1 9   37 4     2
H 4       9 23   1 568
I     8   27 1 4 9 3

Step 28

In row E, each of the cells E1 and E6 can only take one of the numbers 2 or 9. These 2 cells will use up these 2 numbers between them. Therefore the numbers can be eliminated from E2, E5 in row E. The remaining possibilities are marked with small numbers.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8   4 7   39   2 1
E 29 57 1 4 56 29 3   568
F   6   1   8     4
G   1 9   37 4     2
H 4       9 23   1 568
I     8   27 1 4 9 3

Step 29

In column 2, the missing 2 can only go in cell H2 or I2. All of these cells are in box G1-I3. Therefore 2 can be eliminated from other cells in box G1-I3 including I1. The remaining possibilities are marked with small numbers.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8   4 7   39   2 1
E 29 57 1 4 56 29 3   568
F   6   1   8     4
G   1 9   37 4     2
H 4       9 23   1 568
I 6   8   27 1 4 9 3

Step 30

Cell I1 can only contain the number 6 since all other possible numbers have been eliminated.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8   4 7   39   2 1
E 29 57 1 4 56 29 3   568
F   6   1   8     4
G   1 9   37 4     2
H 4       9 23   1 568
I 6   8   27 1 4 9 3

Step 31

Cell G1 can only contain the number 3 since all other numbers are somewhere in its row, column or box.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8   4 7   39   2 1
E 29 57 1 4 56 29 3   568
F   6   1   8     4
G 3 1 9   7 4     2
H 4       9 23   1 568
I 6   8   27 1 4 9 3

Step 32

Because of the number 3 just placed, the only position in row H for another 3 is cell H6.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8   4 7   9   2 1
E 29 57 1 4 56 29 3   568
F   6   1   8     4
G 3 1 9   7 4     2
H 4       9 3   1 568
I 6   8   27 1 4 9 3

Step 33

Because of the number 3 just placed, the only position in column 2 for another 3 is cell D2.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8 3 4 7   9   2 1
E 29 57 1 4 56 29 3   568
F   6   1   8     4
G 3 1 9   7 4     2
H 4       9 3   1 568
I 6   8   27 1 4 9 3

Step 34

Because of the number 3 just placed, the only position in row F for another 3 is cell F5.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8 3 4 7   9   2 1
E 29 57 1 4 56 29 3   568
F   6   1 3 8     4
G 3 1 9   7 4     2
H 4       9 3   1 568
I 6   8   27 1 4 9 3

Step 35

The number 2 is missing from box D4-F6 and its only possible position is cell E6.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8 3 4 7   9   2 1
E 9 57 1 4 56 2 3   568
F   6   1 3 8     4
G 3 1 9   7 4     2
H 4       9 3   1 568
I 6   8   27 1 4 9 3

Step 36

Because of the number 2 just placed, the only position in row F for another 2 is cell F1.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8 3 4 7   9   2 1
E 9 57 1 4 56 2 3   568
F 2 6   1 3 8     4
G 3 1 9   7 4     2
H 4       9 3   1 568
I 6   8   27 1 4 9 3

Step 37

Because of the number 2 just placed, the only position in column 5 for another 2 is cell I5.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8 3 4 7   9   2 1
E 9 57 1 4 56 2 3   568
F 2 6   1 3 8     4
G 3 1 9   7 4     2
H 4       9 3   1 568
I 6   8   2 1 4 9 3

Step 38

Because of the number 2 just placed, the only position in column 2 for another 2 is cell H2.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8 3 4 7   9   2 1
E 9 57 1 4 56 2 3   568
F 2 6   1 3 8     4
G 3 1 9   7 4     2
H 4 2     9 3   1 568
I 6   8   2 1 4 9 3

Step 39

E1 is the last empty cell in column 1 and the missing number is 9.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8 3 4 7   9   2 1
E 9 57 1 4 56 2 3   568
F 2 6   1 3 8     4
G 3 1 9   7 4     2
H 4 2     9 3   1 568
I 6   8   2 1 4 9 3

Step 40

The number 9 does not yet appear in column 6. Due to other 9s on the grid, the only place it can go is cell D6.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8 3 4 7   9   2 1
E 9 57 1 4 56 2 3   568
F 2 6   1 3 8     4
G 3 1 9   7 4     2
H 4 2     9 3   1 568
I 6   8   2 1 4 9 3

Step 41

Because of the number 9 just placed, the only position in row F for another 9 is cell F7.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8 3 4 7   9   2 1
E 9 57 1 4 56 2 3   568
F 2 6   1 3 8 9   4
G 3 1 9   7 4     2
H 4 2     9 3   1 568
I 6   8   2 1 4 9 3

Step 42

The number 7 is missing from row I and its only possible position is cell I2.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8 3 4 7   9   2 1
E 9 5 1 4 56 2 3   568
F 2 6   1 3 8 9   4
G 3 1 9   7 4     2
H 4 2     9 3   1 568
I 6 7 8   2 1 4 9 3

Step 43

Because of the number 7 just placed, the only position in column 3 for another 7 is cell F3.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8 3 4 7   9   2 1
E 9 5 1 4 56 2 3   568
F 2 6 7 1 3 8 9   4
G 3 1 9   7 4     2
H 4 2     9 3   1 568
I 6 7 8   2 1 4 9 3

Step 44

Because of the number 7 just placed, the only position in row E for another 7 is cell E8.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8 3 4 7   9   2 1
E 9 5 1 4 56 2 3 7 568
F 2 6 7 1 3 8 9   4
G 3 1 9   7 4     2
H 4 2     9 3   1 568
I 6 7 8   2 1 4 9 3

Step 45

E2 is the last empty cell in box D1-F3 and the missing number is 5.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8 3 4 7   9   2 1
E 9 5 1 4 6 2 3 7 68
F 2 6 7 1 3 8 9   4
G 3 1 9   7 4     2
H 4 2     9 3   1 568
I 6 7 8   2 1 4 9 3

Step 46

H3 is the last empty cell in column 3 and the missing number is 5.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8 3 4 7   9   2 1
E 9 5 1 4 6 2 3 7 68
F 2 6 7 1 3 8 9   4
G 3 1 9   7 4     2
H 4 2 5   9 3   1 68
I 6 7 8   2 1 4 9 3

Step 47

F8 is the last empty cell in row F and the missing number is 5.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8 3 4 7   9   2 1
E 9 5 1 4 6 2 3 7 68
F 2 6 7 1 3 8 9 5 4
G 3 1 9   7 4     2
H 4 2 5   9 3   1 68
I 6 7 8   2 1 4 9 3

Step 48

Because of the number 5 just placed, the only position in row D for another 5 is cell D5.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8 3 4 7 5 9   2 1
E 9 5 1 4 6 2 3 7 68
F 2 6 7 1 3 8 9 5 4
G 3 1 9   7 4     2
H 4 2 5   9 3   1 68
I 6 7 8   2 1 4 9 3

Step 49

E5 is the last empty cell in box D4-F6 and the missing number is 6.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8 3 4 7 5 9   2 1
E 9 5 1 4 6 2 3 7 8
F 2 6 7 1 3 8 9 5 4
G 3 1 9   7 4     2
H 4 2 5   9 3   1 68
I 6 7 8   2 1 4 9 3

Step 50

D7 is the last empty cell in row D and the missing number is 6.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8 3 4 7 5 9 6 2 1
E 9 5 1 4 6 2 3 7 8
F 2 6 7 1 3 8 9 5 4
G 3 1 9   7 4     2
H 4 2 5   9 3   1 68
I 6 7 8   2 1 4 9 3

Step 51

E9 is the last empty cell in box D7-F9 and the missing number is 8.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8 3 4 7 5 9 6 2 1
E 9 5 1 4 6 2 3 7 8
F 2 6 7 1 3 8 9 5 4
G 3 1 9   7 4     2
H 4 2 5   9 3   1 6
I 6 7 8   2 1 4 9 3

Step 52

Because of the number 8 just placed, the only position in column 8 for another 8 is cell G8.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8 3 4 7 5 9 6 2 1
E 9 5 1 4 6 2 3 7 8
F 2 6 7 1 3 8 9 5 4
G 3 1 9   7 4   8 2
H 4 2 5   9 3   1 6
I 6 7 8   2 1 4 9 3

Step 53

Because of the number 8 just placed, the only position in row H for another 8 is cell H4.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8 3 4 7 5 9 6 2 1
E 9 5 1 4 6 2 3 7 8
F 2 6 7 1 3 8 9 5 4
G 3 1 9   7 4   8 2
H 4 2 5 8 9 3   1 6
I 6 7 8   2 1 4 9 3

Step 54

I4 is the last empty cell in row I and the missing number is 5.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8 3 4 7 5 9 6 2 1
E 9 5 1 4 6 2 3 7 8
F 2 6 7 1 3 8 9 5 4
G 3 1 9   7 4   8 2
H 4 2 5 8 9 3   1 6
I 6 7 8 5 2 1 4 9 3

Step 55

Because of the number 5 just placed, the only position in row G for another 5 is cell G7.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3  
C 5 9 3 2 1   8 4  
D 8 3 4 7 5 9 6 2 1
E 9 5 1 4 6 2 3 7 8
F 2 6 7 1 3 8 9 5 4
G 3 1 9   7 4 5 8 2
H 4 2 5 8 9 3   1 6
I 6 7 8 5 2 1 4 9 3

Step 56

Because of the number 5 just placed, the only position in column 9 for another 5 is cell B9.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4   1   9
B 1 4 6 9 8   2 3 5
C 5 9 3 2 1   8 4  
D 8 3 4 7 5 9 6 2 1
E 9 5 1 4 6 2 3 7 8
F 2 6 7 1 3 8 9 5 4
G 3 1 9   7 4 5 8 2
H 4 2 5 8 9 3   1 6
I 6 7 8 5 2 1 4 9 3

Step 57

Because of the number 5 just placed, the only position in column 6 for another 5 is cell A6.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4 5 1   9
B 1 4 6 9 8   2 3 5
C 5 9 3 2 1   8 4  
D 8 3 4 7 5 9 6 2 1
E 9 5 1 4 6 2 3 7 8
F 2 6 7 1 3 8 9 5 4
G 3 1 9   7 4 5 8 2
H 4 2 5 8 9 3   1 6
I 6 7 8 5 2 1 4 9 3

Step 58

A8 is the last empty cell in row A and the missing number is 6.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4 5 1 6 9
B 1 4 6 9 8   2 3 5
C 5 9 3 2 1   8 4  
D 8 3 4 7 5 9 6 2 1
E 9 5 1 4 6 2 3 7 8
F 2 6 7 1 3 8 9 5 4
G 3 1 9   7 4 5 8 2
H 4 2 5 8 9 3   1 6
I 6 7 8 5 2 1 4 9 3

Step 59

Because of the number 6 just placed, the only position in row C for another 6 is cell C6.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4 5 1 6 9
B 1 4 6 9 8   2 3 5
C 5 9 3 2 1 6 8 4  
D 8 3 4 7 5 9 6 2 1
E 9 5 1 4 6 2 3 7 8
F 2 6 7 1 3 8 9 5 4
G 3 1 9   7 4 5 8 2
H 4 2 5 8 9 3   1 6
I 6 7 8 5 2 1 4 9 3

Step 60

G4 is the last empty cell in column 4 and the missing number is 6.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4 5 1 6 9
B 1 4 6 9 8   2 3 5
C 5 9 3 2 1 6 8 4  
D 8 3 4 7 5 9 6 2 1
E 9 5 1 4 6 2 3 7 8
F 2 6 7 1 3 8 9 5 4
G 3 1 9 6 7 4 5 8 2
H 4 2 5 8 9 3   1 6
I 6 7 8 5 2 1 4 9 3

Step 61

Because of the number 6 just placed, the only position in row H for another 6 is cell H9.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4 5 1 6 9
B 1 4 6 9 8   2 3 5
C 5 9 3 2 1 6 8 4  
D 8 3 4 7 5 9 6 2 1
E 9 5 1 4 6 2 3 7 8
F 2 6 7 1 3 8 9 5 4
G 3 1 9 6 7 4 5 8 2
H 4 2 5 8 9 3   1 6
I 6 7 8 5 2 1 4 9 3

Step 62

B6 is the last empty cell in box A4-C6 and the missing number is 7.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4 5 1 6 9
B 1 4 6 9 8 7 2 3 5
C 5 9 3 2 1 6 8 4  
D 8 3 4 7 5 9 6 2 1
E 9 5 1 4 6 2 3 7 8
F 2 6 7 1 3 8 9 5 4
G 3 1 9 6 7 4 5 8 2
H 4 2 5 8 9 3   1 6
I 6 7 8 5 2 1 4 9 3

Step 63

C9 is the last empty cell in row C and the missing number is 7.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4 5 1 6 9
B 1 4 6 9 8 7 2 3 5
C 5 9 3 2 1 6 8 4 7
D 8 3 4 7 5 9 6 2 1
E 9 5 1 4 6 2 3 7 8
F 2 6 7 1 3 8 9 5 4
G 3 1 9 6 7 4 5 8 2
H 4 2 5 8 9 3   1 6
I 6 7 8 5 2 1 4 9 3

Step 64

G5 is the last empty cell in column 5 and the missing number is 7.

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4 5 1 6 9
B 1 4 6 9 8 7 2 3 5
C 5 9 3 2 1 6 8 4 7
D 8 3 4 7 5 9 6 2 1
E 9 5 1 4 6 2 3 7 8
F 2 6 7 1 3 8 9 5 4
G 3 1 9 6 7 4 5 8 2
H 4 2 5 8 9 3   1 6
I 6 7 8 5 2 1 4 9 3

Step 65

H7 is the last empty cell in row H and the missing number is 7.

Congratulations - the puzzle is solved!

1 2 3 4 5 6 7 8 9
A 7 8 2 3 4 5 1 6 9
B 1 4 6 9 8 7 2 3 5
C 5 9 3 2 1 6 8 4 7
D 8 3 4 7 5 9 6 2 1
E 9 5 1 4 6 2 3 7 8
F 2 6 7 1 3 8 9 5 4
G 3 1 9 6 7 4 5 8 2
H 4 2 5 8 9 3 7 1 6
I 6 7 8 5 2 1 4 9 3
© Web Sudoku - www.websudoku.com