Does the first puzzle actually have a unique solution? I solved grids #3, 6, and 9, but I can't get any further, even with help from SudokuSolver. Richard, where did you get that solution you posted?
Here's what I have:
Grid 1:
Code:
.-------------------------------.-------------------------------.-------------------------------.
| 6 27 27 | 9 8 3 | 5 1 4 |
| 3 15 15 | 6 7 4 | 8 2 9 |
| 8 4 9 | 1 2 5 | 7 3 6 |
:-------------------------------+-------------------------------+-------------------------------:
| 7 289 28 | 4 3 1 | 6 89 5 |
| 4 89 3 | 5 6 7 | 2 89 1 |
| 1 56 56 | 2 9 8 | 3 4 7 |
:-------------------------------+-------------------------------+-------------------------------:
| 9 78 78 | 3 4 6 | 1 5 2 |
| 2 16 16 | 8 5 9 | 4 7 3 |
| 5 3 4 | 7 1 2 | 9 6 8 |
'-------------------------------.-------------------------------.-------------------------------'
Grid 2:
Code:
.-------------------------------.-------------------------------.-------------------------------.
| 3 6 2 | 5 1 4 | 9 78 78 |
| 4 5 9 | 8 7 3 | 2 16 16 |
| 8 1 7 | 6 2 9 | 5 3 4 |
:-------------------------------+-------------------------------+-------------------------------:
| 1 3 4 | 9 6 2 | 78 78 5 |
| 6 2 8 | 7 5 1 | 3 4 9 |
| 7 9 5 | 4 3 8 | 16 16 2 |
:-------------------------------+-------------------------------+-------------------------------:
| 9 8 3 | 2 4 6 | 17 5 17 |
| 5 4 1 | 3 9 7 | 68 2 68 |
| 2 7 6 | 1 8 5 | 4 9 3 |
'-------------------------------.-------------------------------.-------------------------------'
Grid 3: Solved.
Grid 4:
Code:
.-------------------------------.-------------------------------.-------------------------------.
| 4 5 7 | 6 1 2 | 9 8 3 |
| 2 36 36 | 9 7 8 | 5 4 1 |
| 8 19 19 | 4 5 3 | 2 7 6 |
:-------------------------------+-------------------------------+-------------------------------:
| 1 8 2 | 7 9 6 | 4 3 5 |
| 5 39 39 | 1 8 4 | 6 2 7 |
| 6 7 4 | 2 3 5 | 1 9 8 |
:-------------------------------+-------------------------------+-------------------------------:
| 3 4 8 | 5 2 1 | 7 6 9 |
| 7 16 156 | 3 4 9 | 8 15 2 |
| 9 2 15 | 8 6 7 | 3 15 4 |
'-------------------------------.-------------------------------.-------------------------------'
Grid 5:
Code:
.-------------------------------.-------------------------------.-------------------------------.
| 17 5 17 | 4 9 2 | 3 8 6 |
| 68 2 68 | 1 7 3 | 5 9 4 |
| 4 9 3 | 8 6 5 | 2 1 7 |
:-------------------------------+-------------------------------+-------------------------------:
| 9 1 4 | 7 35 8 | 6 2 35 |
| 26 3 56 | 25 1 4 | 9 7 8 |
| 28 7 58 | 9 235 6 | 1 4 35 |
:-------------------------------+-------------------------------+-------------------------------:
| 3 4 2 | 6 8 1 | 7 5 9 |
| 15 6 9 | 25 4 7 | 8 3 12 |
| 157 8 17 | 3 25 9 | 4 6 12 |
'-------------------------------.-------------------------------.-------------------------------'
Grid 6: Solved.
Grid 7:
Code:
.-------------------------------.-------------------------------.-------------------------------.
| 7 6 9 | 1 5 8 | 3 4 2 |
| 8 15 2 | 7 4 3 | 15 6 9 |
| 3 15 4 | 6 9 2 | 157 8 17 |
:-------------------------------+-------------------------------+-------------------------------:
| 2 3 6 | 4 8 9 | 17 5 17 |
| 4 8 5 | 2 1 7 | 9 3 6 |
| 9 7 1 | 5 3 6 | 8 2 4 |
:-------------------------------+-------------------------------+-------------------------------:
| 1 2 7 | 3 6 5 | 4 9 8 |
| 5 4 8 | 9 2 1 | 6 7 3 |
| 6 9 3 | 8 7 4 | 2 1 5 |
'-------------------------------.-------------------------------.-------------------------------'
Grid 8:
Code:
.-------------------------------.-------------------------------.-------------------------------.
| 7 5 9 | 3 8 6 | 4 2 1 |
| 8 3 12 | 7 4 12 | 5 9 6 |
| 4 6 12 | 12 9 5 | 7 8 3 |
:-------------------------------+-------------------------------+-------------------------------:
| 3 9 8 | 4 2 7 | 6 1 5 |
| 1 2 6 | 9 5 3 | 8 4 7 |
| 5 7 4 | 6 1 8 | 2 3 9 |
:-------------------------------+-------------------------------+-------------------------------:
| 2 1 7 | 5 3 4 | 9 6 8 |
| 9 8 5 | 12 6 12 | 3 7 4 |
| 6 4 3 | 8 7 9 | 1 5 2 |
'-------------------------------.-------------------------------.-------------------------------'
Grid 9: Solved.