SUDOKU:
3 worked examples


a step-by-step analysis
of three ‘hard’ grids





EXAMPLE 1

EXAMPLE 2

EXAMPLE 3


If you have difficulty with the more challenging sudoku puzzle grids, but are determined to win through, then you may find this page helpful. Initially, you could print out a copy of any of the puzzle grids and see how you do without the notes.

Normal sudoku rules apply. Each square of the puzzle grid carries a reference number (01 to 81) in the top right corner. Cells are marked by a vertically aligned label in the first square. Rows are assumed counted from the left, and columns from the top. The sweep pattern used in solving is generally 1 to 9, top left to bottom right.




EXAMPLE 1


 example 1 puzzle grid

print out EXAMPLE 1 puzzle grid

digit context square because
2 Cell 2 05 04 blocked (58); 06 blocked (33)
13 blocked (58); 14 taken; 15 blocked (33)
22 taken; 23 blocked (21); 24 taken
2 Cell 4 37 28 blocked (33); 29 blocked (33/65); 30 blocked (21/33)
38 taken; 39 blocked (21)
46 taken; 47 blocked (65); 48 taken
4 Cell 4 47 28 blocked (36); 29 blocked (36); 30 blocked (36/57)
37 taken; 38 taken; 39 blocked (57)
46 taken; 48 taken
8 Cell 1 03 01 taken; 02 blocked (38)
10 blocked (17); 11 taken; 12 blocked (17)
19 blocked (22); 20 blocked (22/38); 21 taken
8 Cell 6 54 34 taken; 35 blocked (17); 36 taken
43 blocked (38/61); 44 taken; 45 blocked (38)
52 blocked (61); 53 blocked (17)
8 Cell 5 32 31 blocked (22); 33 taken
40 blocked (22/38); 41 blocked (38); 42 blocked (38)
49 taken; 50 blocked (54); 51 blocked (54)
5 Cell 1 02 01 taken; 03 taken
10 blocked (14); 11 taken; 12 blocked (14)
19 blocked (25); 20 blocked (25); 21 taken
5 Cell 7 55 in Cell 8:
58 taken; 59 blocked (14); 60 taken
68 taken
76 blocked (81); 77 blocked (14/81); 78 blocked (81)
therefore:
the 5 for Cell 8 must go 67 or 69 - whichever, the rest of Row 8 is blocked
in Cell 7:
56 blocked (02); 57 taken
64 blocked (67 or 69); 65 taken; 66 blocked (67 or 69)
73 blocked (81); 74 blocked (02/81); 75 blocked (81)
9 Row 7 59 55 taken; 56 blocked (11); 57 taken
58 taken; 60 taken
61 taken; 62 blocked (71); 63 blocked (71)
9 Cell 3 27 in Cell 2:
05 taken
13 blocked (11); 14 taken; 15 blocked (11)
22 taken; 23 blocked (59); 24 taken
therefore:
the 9 for Cell 2 must go 04 or 06 - whichever, the rest of Row 1 is blocked
in Cell 3:
07 blocked (04 or 06); 08 blocked (04 or 06/71); 09 blocked (04 or 06)
16 blocked (11); 17 taken; 18 blocked (11)
25 taken; 26 blocked (71)
2 Col 9 18 09 blocked (05); 27 taken
36 taken; 45 blocked (37); 54 taken
63 blocked (58); 72 blocked (65); 81 taken
3 Cell 8 77 58 taken; 59 taken; 60 taken
67 blocked (49); 68 taken; 69 blocked (24)
76 blocked (49); 78 blocked (24)
7 Cell 5 50 blocked to 1 (46/68); 2 (05/33); 3 (49/77)
4 (47); 5 (14); 6 (48)
8 (32/54); 9 (59)
7 Cell 3 26 in Cell 2:
04 blocked (01); 05 taken; 06 blocked (01)
14 taken
22 taken; 23 blocked (50); 24 taken
therefore:
the 7 for Cell 2 must go 13 or 15 - whichever, the rest of Row 2 is blocked
in Cell 3:
07 blocked (01); 08 blocked (01); 09 blocked (01)
16 blocked (13 or 15); 17 taken; 18 taken
25 taken; 27 taken
1 Cell 9 62 blocked to 2 (58); 3 (44)
4 (57); 5 (55/81); 6 (60)
7 (26); 8 (17/61); 9 (59/71)
1 Cell 3 09 07 blocked (34); 08 blocked (62)
16 blocked (34); 17 taken; 18 taken
25 taken; 26 taken; 27 taken
3 Row 1 07 01 taken; 02 taken; 03 taken
04 blocked (24/49); 05 taken; 06 blocked (24)
08 blocked (44); 09 taken
1 Row 3 20 19:
1 is blocked (46); 2 (21/37); 3 (24)
5 (02/25/55)
7 (01/26); 8 (03/22); 9 (11/27)
23:
1 is blocked (68); 2 (05/21); 3 (24/77)
5 (14/25)
7 (26/50); 8 (22/32); 9 (27/59)
therefore:
4 and 6 each must go 19 or 23 - whichever, the rest of Row 3 is blocked to these digits (= a couple)
20:
2 is blocked (21/65); 3 (24)
4 (19 or 23); 5 (02/25); 6 (19 or 23)
7 (01/26); 8 (03/22/38); 9 (11/27)
3 Cell 1 12 blocked to 1 (20); 2 (18/21)
4 (57); 5 (02/14); 6 (48)
7 (01); 8 (03/17); 9 (11)
7 Cell 7 66 blocked to 1 (68); 2 (21/65); 3 (12)
4 (57); 5 (55); 6 (48)
8 (03); 9 (71)
3 Cell 7 56 blocked to 1 (20/62); 2 (58/65)
4 (47/57); 5 (02/55); 6 (60)
7 (66); 8 (38/61); 9 (11/59)
7 Row 7 63 the only digit not placed
Row 7 is complete
7 Cell 6 43 34 taken; 35 blocked (26); 36 taken
44 taken; 45 blocked (63)
52 blocked (50); 53 blocked (26/50); 54 taken
7 Cell 4 29 28 blocked (01); 30 blocked (66)
37 taken; 38 taken; 39 blocked (43/66)
46 taken; 47 taken; 48 taken
6 Col 2 74 the only digit not placed
Column 2 is complete
3 Cell 4 28 29 taken; 30 blocked (12)
37 taken; 38 taken; 39 blocked (12/44)
46 taken; 47 taken; 48 taken
3 Cell 9 72 61 taken; 62 taken; 63 taken
70 blocked (07); 71 taken
79 blocked (07/77); 80 blocked (44/77); 81 taken
Digit 3 in every cell
6 Col 9 45 the only digit not placed
Column 9 is complete
6 Cell 9 70 61 taken; 62 taken; 63 taken
71 taken; 72 taken
79 blocked (74); 80 blocked (74); 81 taken
6 Cell 3 08 07 taken; 09 taken
16 blocked (70); 17 taken; 18 taken
25 taken; 26 taken; 27 taken
4 Cell 3 16 the only digit not placed
Cell 3 is complete
4 Cell 1 19 01 taken; 02 taken; 03 taken
10 blocked (16); 11 taken; 12 taken
20 taken; 21 taken
6 Cell 1 10 the only digit not placed
Cell 1 is complete
6 Row 3 23 the only digit not placed
Row 3 is complete
4 Col 5 41 the only digit not placed
Column 5 is complete
5 Cell 6 35 blocked to 1 (34/62); 2 (33); 3 (28/44)
4 (36); 6 (08/45)
7 (26/29/43); 8 (17/32/54); 9 (71)
9 Cell 6 52 34 taken; 35 taken; 36 taken
43 taken; 44 taken; 45 taken
53 blocked (71); 54 taken
2 Cell 6 53 the only digit not placed
Cell 6 is complete
5 Row 6 51 the only digit not placed
Row 6 is complete
2 Col 7 79 the only digit not placed
Column 7 is complete
Digit 2 in every cell
4 Col 8 80 the only digit not placed
Column 8 is complete
Cell 9 is complete
6 Cell 5 31 32 taken; 33 taken
40 blocked (45); 41 taken; 42 blocked (45)
49 taken; 50 taken; 51 taken
Digit 6 in every cell
8 Cell 7 64 blocked to 1 (46/68); 2 (37/58/65); 3 (28/56/72)
4 (19); 5 (55); 6 (10/70/74)
7 (01/66); 9 (71)
9 Col 1 73 the only digit not placed
Column 1 is complete
1 Cell 7 75 the only digit not placed
Cell 7 is complete
5 Row 5 39 40:
2 is blocked (33/37/58); 3 (44/49)
4 (41); 5 (51); 6 (31/45)
7(43/50); 8 (22/32/38)
42:
2 is blocked (33/37); 3 (24/44/49)
4 (41); 5 (51): 6 (31/45/60)
7 (43/50); 8 (32/38)
therefore:
1 and 9 each must go 40 or 42 - whichever, the rest of Row 5 is blocked to these digits (= a couple)
39:
1 is blocked (40 or 42/46/75); 2 (21/37); 3 (12/28/44)
4 (41/47/57); 6 (45/48)
7 (29/43/66); 8 (03/38); 9 (40 or 42)
9 Cell 4 30 the only digit not placed
Cell 4 is complete
Row 4 is complete
Column 3 is complete
7 Cell 8 76 blocked to 1 (68/75); 2 (58/79); 3 (49/77)
4 (80); 5 (81); 6 (31/60/74)
8 (22); 9 (59/73)
8 Row 9 78 the only digit not placed
Row 9 is complete
Digit 8 in every cell
7 Cell 2 15 04 blocked (01/76); 05 taken; 06 blocked (01)
13 blocked (76); 14 taken
22 taken; 23 taken; 24 taken
Digit 7 in every cell
1 Row 2 13 the only digit not placed
Row 2 is complete
1 Cell 5 42 31 taken; 32 taken; 33 taken
40 blocked (13); 41 taken
49 taken; 50 taken; 51 taken
Digit 1 in every cell
9 Cell 5 40 the only digit not placed
Cell 5 is complete
Row 5 is complete
9 Cell 2 06 04 blocked (40); 05 taken
13 taken; 14 taken; 15 taken
22 taken; 23 taken; 24 taken
Digit 9 in every cell
4 Cell 2 04 the only digit not placed
Cell 2 is complete
Row 1 is complete
5 Col 4 67 the only digit not placed
Column 4 is complete
Digit 5 in every cell
4 Cell 8 69 the only digit not placed
Cell 8 is complete
Row 8 is complete
Column 6 is complete
Digit 4 in every cell
The grid is complete

TOP

BOTTOM




EXAMPLE 2


 example 2 puzzle grid

print out EXAMPLE 2 puzzle grid


digit context square because
1 Cell 5 33 31 taken; 32 blocked (77)
40 taken; 41 blocked (77); 42 taken
49 blocked (53); 50 blocked (53/77); 51 taken
4 Cell 5 49 31 taken; 32 blocked (05); 33 taken
40 taken; 41 blocked (05/39); 42 taken
50 blocked (05); 51 taken
6 Cell 5 41 31 taken; 32 blocked (28); 33 taken
40 taken; 42 taken
49 taken; 50 blocked (54); 51 taken
7 Cell 6 44 34 blocked (29); 35 blocked (29); 36 blocked (29/63)
43 taken; 45 blocked (63)
52 blocked (51); 53 taken; 54 taken
5 Cell 8 59 in Cell 5:
31 taken; 33 taken
40 taken; 41 taken; 42 taken
49 taken; 51 taken
Digits 3 and 9 to place
therefore:
3 and 9 each must go 32 or 50 - whichever, the rest of Column 5 is blocked to these digits (= a couple)
in Cell 8
59 blocked to 1 (77); 2 (57); 3 (32 or 50)
4 (05); 6 (41/67): 7 (63)
8 (62); 9 (32 or 50)
9 Cell 6 45 in Row 4:
30 blocked to 1 (33); 2 (57)
4 (39); 5(31); 6 (28)
7 (29); 8 (12)
therefore:
3 or 9 must go 30
also:
3 or 9 must go 32 (see previous step) - whichever, the rest of Row 4 is blocked to these digits (= a couple)
in Cell 6:
34 blocked (25/30 or 32); 35 blocked (30 or 32); 36 blocked (30 or 32)
43 taken; 44 taken
52 blocked (25); 53 taken; 54 taken
3 Cell 6 52 34 blocked (30 or 32); 35 blocked (17/30 or 32); 36 blocked (30 or 32)
43 taken; 44 taken; 45 taken
53 taken; 54 taken
9 Cell 5 50 blocked to 1 (33/53/77); 2 (40); 3 (52)
4 (05/49); 5 (31/59); 6 (41/54)
7 (51); 8 (42)
3 Cell 5 32 the only digit not placed
Cell 5 is complete
9 Row 4 30 remaining half of couple (see earlier)
9 Cell 9 80 61 blocked (25); 62 taken; 63 taken
70 taken; 71 blocked (65); 72 blocked (45/65)
79 blocked (25); 81 blocked (45)
5 Cell 4 48 blocked to 1 (53); 2 (57); 3 (52)
4 (39/49); 6 (28/54)
7 (29/51); 8 (12); 9 (30/50)
6 Row 2 11 in Cell 9:
62 taken; 63 taken
70 taken; 71 blocked (67); 72 blocked (54/67)
80 taken; 81 blocked (54)
therefore:
the 6 for Cell 9 must go 61 or 79 - whichever, the rest of Column 7 is blocked
in Row 2:
10 blocked (28); 12 taken
13 blocked (67); 14 blocked (41); 15 taken
16 blocked (61 or 79); 17 taken; 18 blocked (54)
4 Cell 1 10 01 blocked (05); 02 blocked (05); 03 blocked (05/39)
11 taken; 12 taken
19 taken; 20 taken; 21 blocked (39)
9 Cell 1 01 02 blocked (65); 03 blocked (30)
10 taken; 11 taken; 12 taken
19 taken; 20 taken; 21 blocked (25/30)
2 Cell 1 02 01 taken; 03 blocked (57)
10 taken; 11 taken; 12 taken
19 taken; 20 taken; 21 blocked (57)
2 Cell 4 46 28 taken; 29 taken; 30 taken
37 blocked (40); 38 blocked (02/40); 39 taken
47 blocked (02); 48 taken
8 Row 6 47 the only digit not placed
Row 6 is complete
6 Cell 7 75 55 blocked (28); 56 blocked (11); 57 taken
64 blocked (28/67); 65 taken; 66 blocked (67)
73 blocked (28); 74 blocked (11)
6 Cell 9 61 62 taken; 63 taken
70 taken; 71 blocked (67); 72 blocked (54/67)
79 blocked (75); 80 taken; 81 blocked (54/75)
7 Cell 7 66 55 blocked (19/63); 56 blocked (29/63) 57 taken
64 blocked (19); 65 taken
73 blocked (19); 74 blocked (29); 75 taken
7 Cell 8 76 58 blocked (63); 59 taken; 60 blocked (51/63)
67 taken; 68 blocked (66); 69 blocked (51/66)
77 taken; 78 blocked (51)
7 Cell 2 14 04 blocked (76); 05 taken; 06 blocked (51)
13 blocked (76); 15 taken
22 blocked (19/76); 23 blocked (19); 24 blocked (19/51)
7 Cell 3 07 08 blocked (44); 09 blocked (63)
16 blocked (14); 17 taken; 18 blocked (14/63)
25 taken; 26 blocked (19/44); 27 blocked (19/63)
Digit 7 in every cell
2 Cell 3 16 blocked to 1 (70); 3 (17/52)
4 (10); 5 (15/43); 6 (11/61)
7 (07/14); 8 (12); 9 (25)
1 Cell 3 18 blocked to 2 (16); 3 (17)
4 (10); 5 (15); 6 (11/54)
7 (07/63); 8 (12); 9 (25/45)
9 Row 2 13 the only digit not placed
Row 2 is complete
4 Cell 9 79 blocked to 1 (70/77); 2 (16); 3 (52)
5 (43); 6 (61/75)
7 (07/63/76); 8 (62); 9 (25/80)
8 Col 7 34 the only digit not placed
Column 7 is complete
4 Cell 7 56 55 blocked (10); 57 taken
64 blocked (10); 65 taken; 66 taken
73 blocked (10/79); 74 blocked (79); 75 taken
3 Cell 7 74 blocked to 1 (77); 2 (02/57)
4 (56/79); 5 (20); 6 (11/75)
7 (29/66/76); 8 (47); 9 (65/80)
1 Col 2 38 the only digit not placed
Column 2 is complete
3 Cell 4 37 the only digit not placed
Cell 4 is complete
Row 5 is complete
1 Cell 7 55 56 taken; 57 taken
64 blocked (70); 65 taken; 66 taken
73 blocked (77); 74 taken; 75 taken
3 Cell 8 58 blocked to 1 (55/77); 2 (40/57)
4 (49/56); 5 (31/59); 6 (61/67)
7 (63/76); 8 (62); 9 (13)
9 Row 7 60 the only digit not placed
Row 7 is complete
Digit 9 in every cell
4 Cell 8 69 58 taken; 59 taken; 60 taken
67 taken; 68 blocked (05)
76 taken; 77 taken; 78 blocked (79)
8 Cell 8 68 58 taken; 59 taken; 60 taken
67 taken; 69 taken
76 taken; 77 taken; 78 blocked (42)
2 Cell 8 58 the only digit not placed
Cell 8 is complete
8 Cell 7 73 55 taken; 56 taken; 57 taken
64 blocked (68); 65 taken; 66 taken
74 taken; 75 taken
5 Cell 7 64 the only digit not placed
Cell 7 is complete
Column 1 is complete
5 Row 9 81 the only digit not placed
Row 9 is complete
3 Cell 9 72 61 taken; 62 taken; 63 taken
70 taken; 71 blocked (17)
79 taken; 80 taken; 81 taken
2 Cell 9 71 the only digit not placed
Cell 9 is complete
Row 8 is complete
2 Cell 6 36 34 taken; 35 blocked (71)
43 taken; 44 Taken; 45 taken
52 taken; 53 taken; 54 taken
4 Cell 6 35 the only digit not placed
Cell 6 is complete
Row 4 is complete
2 Col 5 23 the only digit not placed
Column 5 is complete
Digit 2 in every cell
4 Cell 3 27 07 taken; 08 blocked (05/35); 09 blocked (05)
16 taken; 17 Taken; 18 taken
25 taken; 26 blocked (35)
Digit 4 in every cell
8 Col 9 09 the only digit not placed
Column 9 is complete
5 Cell 3 08 07 taken; 09 taked
16 taken; 17 Taken; 18 taken
25 taken; 26 blocked (20); 27 taken
Digit 5 in every cell
6 Cell 3 26 the only digit not placed
Cell 3 is complete
Column 8 is complete
8 Cell 2 22 04 blocked (09); 05 taken; 06 blocked (09/42)
13 taken; 14 Taken; 15 taken
23 taken; 24 blocked (42)
Digit 8 in every cell
1 Col 4 04 the only digit not placed
Column 4 is complete
1 Cell 1 21 01 taken; 02 taken; 03 blocked (04)
10 taken; 11 Taken; 12 taken
19 taken; 20 taken
Digit 1 in every cell
3 Row 3 24 the only digit not placed
Row 3 is complete
3 Cell 1 03 the only digit not placed
Cell 1 is complete
Column 3 is complete
Digit 3 in every cell
6 Cell 2 06 the only digit not placed
Cell 2 is complete
Row 1 is complete
Column 6 is complete
Digit 6 in every cell
The grid is complete

TOP

BOTTOM




EXAMPLE 3


 example 3 puzzle grid

print out EXAMPLE 3 puzzle grid


digit context square because
1 Cell 9 79 61 taken; 62 blocked (26); 63 blocked (54)
70 blocked (64); 71 blocked (26/64); 72 blocked (54/64)
80 blocked (26); 81 taken
2 Cell 6 45 in Cell 3:
07 blocked (61); 09 taken
16 blocked (61); 18 taken
25 blocked (21/61); 26 taken; 27 blocked (21)
therefore:
the 2 for Cell 3 must go 08 or 17 - whichever, the rest of Column 8 blocked
in Cell 6:
34 taken; 35 blocked (08 or 17/33); 36 blocked (33)
43 blocked (61); 44 blocked (08 or 17)
52 blocked (61); 53 taken; 54 taken
2 Cell 4 46 in Cell 7:
55 blocked (61); 56 taken; 57 blocked (21/61)
64 taken; 66 blocked (21)
73 taken; 75 blocked (21)
therefore:
the 2 for Cell 7 must go 65 or 74 - whichever, the rest of Column 2 is blocked
in Cell 4:
28 taken; 29 taken; 30 blocked (21/33)
37 blocked (45); 38 blocked (45/65 or 74); 39 blocked (21/45)
47 blocked (65 or 74); 48 taken
4 Cell 6 36 blocked to 1 (54); 2 (33/45); 3 (28)
5 (53); 6 (09)
7 (29); 8 (18); 9 (34/81)
5 Cell 8 78 in Cell 9:
61 taken; 62 blocked (53/56); 63 blocked (56)
71 blocked (53)
79 taken; 80 blocked (53); 81 taken
therefore:
the 5 for Cell 9 must go 70 or 72 - whichever, the rest of Row 8 is blocked
in Cell 8:
58 blocked (56); 59 taken; 60 blocked (56)
67 blocked (70 or 72); 68 taken; 69 blocked (70 or 72)
76 taken; 77 blocked (14)
7 Cell 9 63 blocked to 1 (54); 2 (45/61); 3 (59)
4 (36); 5 (56); 6 (09)
8 (18); 9 (81)
1 Cell 5 32 blocked to 2 (33); 3 (28/59)
4 (36); 5 (14); 6 (23/49)
7 (29); 8 (68); 9 (34)
6 Cell 6 35 in Cell 9 for Digit 8:
61 taken; 63 taken
70 blocked (68); 71 blocked (68); 72 blocked (18/68)
79 taken; 81 taken
therefore:
the 8 for Cell 9 must go 62 or 80 - whichever, the rest of Column 8 is blocked
in Cell 6:
35 blocked to 1 (26/32/54); 2 (33/45); 3 (28)
4 (36); 5 (53)
7 (29); 8 (62 or 80); 9 (34)
6 Cell 9 70 61 taken; 62 blocked (35); 63 taken
71 blocked (35); 72 blocked (09)
79 taken; 80 blocked (35/73); 81 taken
6 Cell 8 60 58 blocked (49); 59 taken
67 blocked (49/70); 68 taken; 69 blocked (70)
76 taken; 77 blocked (23/73); 78 taken
1 Cell 8 58 59 taken; 60 taken
67 blocked (64); 68 taken; 69 blocked (64)
76 taken; 77 blocked (32/79); 78 taken
1 Cell 2 15 04 blocked (58); 05 blocked (32); 06 taken
13 blocked (58); 14 taken
22 blocked (26/58); 23 taken; 24 blocked (26)
4 Cell 2 24 04 blocked (01/76); 05 blocked (01); 06 taken
13 blocked (76); 14 taken; 15 taken
22 blocked (76); 23 taken
4 Cell 3 16 in Cell 9:
61 taken; 63 taken
70 taken; 72 blocked (36)
79 taken; 80 blocked (76); 81 taken
therefore:
the 4 for Cell 9 must go 62 or 71 - whichever, the rest of Column 8 blocked
in Cell 3:
07 blocked (01); 08 blocked (62 or 71); 09 taken
17 blocked (62 or 71); 18 taken
25 blocked (24); 26 taken; 27 blocked (24/36)
5 Cell 9 72 61 taken; 62 blocked (53/56); 63 taken
70 taken; 71 blocked (53)
79 taken; 80 blocked (53/78); 81 taken
3 Col 9 27 the only digit not placed
Column 9 is complete
7 Cell 6 44 in Cell 9 for Digit 3:
61 taken; 62 blocked (59); 63 taken
70 taken; 72 taken
79 taken; 81 taken
therefore:
the 3 for Cell 9 must go 71 or 80 - whichever, the rest of Column 8 is blocked
in Cell 6:
44 blocked to 1 (26/54); 2 (45); 3 (71 or 80)
4 (36); 5 (53); 6 (35)
8 (62 or 80 - see earlier); 9 (34)
9 Row 7 55 56 taken; 57 blocked (48)
58 taken; 59 taken; 60 taken
61 taken; 62 blocked (81); 63 taken
7 Cell 1 10 blocked to 1 (15/64); 2 (21/46); 3 (28)
4 (01/16); 5 (14); 6 (73)
8 (18); 9 (55)
4 Cell 4 47 30:
1 is blocked (32); 2 (21/33/46); 3 (28)
4 (36); 6 (35)
7(29); 9 (34/48)
37:
1 is blocked (64); 2 (45/46); 3 (28)
4 (01); 6 (73)
7 (29/44); 9 (48/55)
therefore:
5 and 8 each must go 30 or 37 - whichever, the rest of Cell 4 is blocked to these digits (= a couple)
47:
1 is blocked (54); 2 (46); 3 (28)
5 (30 or 37/53/56); 6 (49)
7 (29); 8 (30 or 37); 9 (48)
7 Cell 5 50 blocked to 1 (32/54); 2 (33/46); 3 (59)
4 (47); 5 (14/53); 6 (23/49)
8 (68); 9 (48)
3 Cell 5 51 blocked to 1 (15/32/54); 2 (33/46)
4 (24/47); 5 (53/78); 6 (49/60)
7 (50); 8 (06); 9 (48)
8 Row 6 52 the only digit not placed
Row 6 is complete
3 Cell 6 43 the only digit not placed
Cell 6 is complete
9 Cell 5 42 blocked to 1 (15/32); 2 (33/45); 3 (43/51)
4 (24); 5 (78); 6 (49/60)
7 (44/50); 8 (06)
7 Col 6 69 the only digit not placed
Column 6 is complete
4 Cell 5 41 31 blocked (36/76); 32 taken; 33 taken
40 blocked (76); 42 taken
49 taken; 50 taken; 51 taken
2 Cell 8 77 blocked to 1 (32/58/79); 3 (59)
4 (76); 5 (14/78); 6 (23/60/73)
7 (50/69); 8 (68); 9 (81)
9 Cell 8 67 the only digit not placed
Cell 8 is complete
9 Col 5 05 the only digit not placed
Column 5 is complete
2 Cell 7 65 55 taken; 56 taken; 57 blocked (21/61)
64 taken; 66 blocked (21)
73 taken; 74 blocked (77); 75 blocked (21/77)
7 Cell 7 75 55 taken; 56 taken; 57 blocked (63)
64 taken; 65 taken; 66 blocked (69)
73 taken; 74 blocked (29)
9 Cell 3 17 07 blocked (05/34); 08 blocked (05); 09 taken
16 taken; 18 taken
25 blocked (34); 26 taken; 27 taken
9 Cell 1 20 01 taken; 02 blocked (05); 03 blocked (05/48)
10 taken; 11 blocked (17); 12 blocked (17/48)
19 blocked (55); 21 taken
Digit 9 in every cell
2 Cell 3 08 07 blocked (61); 09 taken
16 taken; 17 taken; 18 taken
25 blocked (21/61); 26 taken; 27 taken
2 Cell 2 13 04 blocked (08); 05 taken; 06 taken
14 taken; 15 taken
22 blocked (21); 23 taken; 24 taken
Digit 2 in every cell
3 Cell 2 04 05 taken; 06 taken
13 taken; 14 taken; 15 taken
22 blocked (27); 23 taken; 24 taken
7 Cell 2 22 the only digit not placed
Cell 2 is complete
7 Cell 3 07 08 taken; 09 taken
16 taken; 17 taken; 18 taken
25 blocked (22); 26 taken; 27 taken
Digit 7 in every cell
5 Cell 3 25 the only digit not placed
Cell 3 is complete
Column 7 is complete
8 Row 3 19 the only digit not placed
Row 3 is complete
5 Cell 1 03 01 taken; 02 blocked (56)
10 taken; 11 blocked (14/56); 12 blocked (14)
19 taken; 20 taken; 21 taken
5 Cell 4 37 the only digit not placed
Column 1 is complete
8 Cell 4 30 remaining half of couple (see earlier)
5 Cell 5 31 32 taken; 33 taken
40 blocked (37); 41 taken; 42 taken
49 taken; 50 taken; 51 taken
Row 4 is complete
Digit 5 in every cell
8 Cell 5 40 the only digit not placed
Cell 5 is complete
Column 4 is complete
8 Cell 7 74 55 taken; 56 taken; 57 blocked (30)
64 taken; 65 taken; 66 blocked (30/68)
73 taken; 75 taken
3 Row 9 80 the only digit not placed
Row 9 is complete
8 Cell 9 62 61 taken; 63 taken
70 taken; 71 blocked (68); 72 taken
79 taken; 80 taken; 81 taken
Digit 8 in every cell
4 Cell 9 71 the only digit not placed
Cell 9 is complete
Column 8 is complete
4 Row 7 57 the only digit not placed
Row 7 is complete
Digit 4 in every cell
3 Cell 7 66 the only digit not placed
Cell 7 is complete
Row 8 is complete
1 Row 1 02 the only digit not placed
Row 1 is complete
1 Cell 4 39 28 taken; 29 taken; 30 taken
37 taken; 38 blocked (02)
46 taken; 47 taken; 48 taken
Digit 1 in every cell
6 Cell 4 38 the only digit not placed
Cell 4 is complete
Row 5 is complete
3 Col 2 11 the only digit not placed
Column 2 is complete
Digit 3 in every cell
6 Cell 1 12 the only digit not placed
Cell 1 is complete
Row 2 is complete
Column 3 is complete
Digit 6 in every cell
The grid is complete

TOP






urbanrim.org.uk
©   2007

Please mention this source in any reproduction


HOME PAGE