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Sudoku #10 — the solutions

The three Sudoku boards from October 10, 2026 — Easy, Medium and Hard — each with its solved grid and a path through it, step by step, that never needs a guess.

Easy — 36 digits given

Every cell falls to scanning: a digit with only one place left in a row, a column or a box.

The board

6 · · | 4 7 1 | 3 2 ·
9 2 · | · · · | 6 · ·
· 4 · | · · 2 | 8 · 5
------+-------+------
· 3 · | · · · | 5 8 7
· · · | 3 · 7 | · · ·
5 7 9 | · · · | · 3 ·
------+-------+------
4 · 2 | 8 · · | · 1 ·
· · 1 | · · · | · 6 8
· 9 8 | 1 3 6 | · · 4

The solution

6 8 5 | 4 7 1 | 3 2 9
9 2 7 | 5 8 3 | 6 4 1
1 4 3 | 9 6 2 | 8 7 5
------+-------+------
2 3 4 | 6 1 9 | 5 8 7
8 1 6 | 3 5 7 | 4 9 2
5 7 9 | 2 4 8 | 1 3 6
------+-------+------
4 6 2 | 8 9 5 | 7 1 3
3 5 1 | 7 2 4 | 9 6 8
7 9 8 | 1 3 6 | 2 5 4

A path through it

The order a solver takes — always the cheapest move left, so a pattern is only reached for when the singles run dry. 45 steps; yours need not match, and any order that never guesses ends on the same grid.

  1. Row 3, column 1 is 1. 1 has only one place left in the top-left box.
  2. Row 1, column 2 is 8. 8 has only one place left in the top-left box.
  3. Row 2, column 6 is 3. 3 has only one place left in the top-center box.
  4. Row 3, column 3 is 3. 3 has only one place left in the top-left box.
  5. Row 2, column 3 is 7. 7 has only one place left in the top-left box.
  6. Row 1, column 3 is 5. 5 has only one place left in the top-left box.
  7. Row 2, column 5 is 8. 8 has only one place left in the top-center box.
  8. Row 2, column 4 is 5. 5 has only one place left in the top-center box.
  9. Row 2, column 9 is 1. 1 has only one place left in the top-right box.
  10. Row 2, column 8 is 4. 4 has only one place left in the top-right box.
  11. Row 3, column 8 is 7. 7 has only one place left in the top-right box.
  12. Row 1, column 9 is 9. 9 has only one place left in the top-right box.
  13. Row 5, column 2 is 1. 1 has only one place left in the middle-left box.
  14. Row 5, column 1 is 8. 8 has only one place left in the middle-left box.
  15. Row 4, column 1 is 2. 2 has only one place left in the middle-left box.
  16. Row 5, column 5 is 5. 5 has only one place left in the center box.
  17. Row 6, column 6 is 8. 8 has only one place left in the center box.
  18. Row 6, column 7 is 1. 1 has only one place left in the middle-right box.
  19. Row 4, column 5 is 1. 1 has only one place left in the center box.
  20. Row 5, column 7 is 4. 4 has only one place left in the middle-right box.
  21. Row 4, column 3 is 4. 4 has only one place left in the middle-left box.
  22. Row 5, column 3 is 6. 6 has only one place left in the middle-left box.
  23. Row 6, column 5 is 4. 4 has only one place left in the center box.
  24. Row 6, column 4 is 2. 2 has only one place left in the center box.
  25. Row 4, column 4 is 6. 6 has only one place left in the center box.
  26. Row 3, column 5 is 6. 6 has only one place left in the top-center box.
  27. Row 3, column 4 is 9. 9 has only one place left in the top-center box.
  28. Row 4, column 6 is 9. 9 has only one place left in the center box.
  29. Row 5, column 9 is 2. 2 has only one place left in the middle-right box.
  30. Row 6, column 9 is 6. 6 has only one place left in the middle-right box.
  31. Row 5, column 8 is 9. 9 has only one place left in the middle-right box.
  32. Row 8, column 1 is 3. 3 has only one place left in the bottom-left box.
  33. Row 7, column 2 is 6. 6 has only one place left in the bottom-left box.
  34. Row 8, column 2 is 5. 5 has only one place left in the bottom-left box.
  35. Row 9, column 1 is 7. 7 has only one place left in the bottom-left box.
  36. Row 8, column 5 is 2. 2 has only one place left in the bottom-center box.
  37. Row 8, column 6 is 4. 4 has only one place left in the bottom-center box.
  38. Row 7, column 6 is 5. 5 has only one place left in the bottom-center box.
  39. Row 8, column 4 is 7. 7 has only one place left in the bottom-center box.
  40. Row 7, column 5 is 9. 9 has only one place left in the bottom-center box.
  41. Row 9, column 7 is 2. 2 has only one place left in the bottom-right box.
  42. Row 7, column 9 is 3. 3 has only one place left in the bottom-right box.
  43. Row 9, column 8 is 5. 5 has only one place left in the bottom-right box.
  44. Row 7, column 7 is 7. 7 has only one place left in the bottom-right box.
  45. Row 8, column 7 is 9. 9 has only one place left in the bottom-right box.

Medium — 28 digits given

Beyond singles, this board asks for a pointing line (2 times).

The board

· · · | 3 9 · | · · ·
3 · · | 6 · · | 1 2 ·
· 5 · | · · 7 | 4 9 ·
------+-------+------
4 9 · | · · · | · · 2
· · 6 | · · · | 8 · ·
2 · · | · · · | · 4 5
------+-------+------
· 7 4 | 5 · · | · 3 ·
· 6 5 | · · 2 | · · 8
· · · | · 7 9 | · · ·

The solution

7 4 2 | 3 9 1 | 5 8 6
3 8 9 | 6 4 5 | 1 2 7
6 5 1 | 2 8 7 | 4 9 3
------+-------+------
4 9 7 | 1 5 8 | 3 6 2
5 3 6 | 9 2 4 | 8 7 1
2 1 8 | 7 6 3 | 9 4 5
------+-------+------
8 7 4 | 5 1 6 | 2 3 9
9 6 5 | 4 3 2 | 7 1 8
1 2 3 | 8 7 9 | 6 5 4

A path through it

The order a solver takes — always the cheapest move left, so a pattern is only reached for when the singles run dry. 55 steps; yours need not match, and any order that never guesses ends on the same grid.

  1. Row 2, column 3 is 9. 9 has only one place left in the top-left box.
  2. Row 3, column 9 is 3. 3 has only one place left in the top-right box.
  3. Row 1, column 8 is 8. 8 has only one place left in the top-right box.
  4. Row 1, column 7 is 5. 5 has only one place left in the top-right box.
  5. Row 1, column 9 is 6. 6 has only one place left in the top-right box.
  6. Row 3, column 1 is 6. 6 has only one place left in the top-left box.
  7. Row 2, column 9 is 7. 7 has only one place left in the top-right box.
  8. Row 5, column 1 is 5. 5 has only one place left in the middle-left box.
  9. Row 8, column 5 is 3. 3 has only one place left in the bottom-center box.
  10. Row 9, column 9 is 4. 4 has only one place left in the bottom-right box.
  11. Row 8, column 4 is 4. 4 has only one place left in the bottom-center box.
  12. Row 9, column 8 is 5. 5 has only one place left in the bottom-right box.
  13. Row 7, column 7 is 2. 2 has only one place left in row 7.
  14. Row 9, column 7 is 6. 6 has only one place left in the bottom-right box.
  15. Row 4, column 8 is 6. 6 has only one place left in the middle-right box.
  16. Row 1, column 1 is 7. 7 has only one place left in column 1.
  17. In the top-center box, 2 can only sit in row 3, so it leaves the rest of that row.
  18. In the middle-right box, 1 can only sit in row 5, so it leaves the rest of that row.
  19. Row 5, column 2 is 3. Nothing but 3 is left for this cell.
  20. Row 9, column 3 is 3. 3 has only one place left in the bottom-left box.
  21. Row 9, column 2 is 2. 2 has only one place left in the bottom-left box.
  22. Row 1, column 3 is 2. 2 has only one place left in the top-left box.
  23. Row 5, column 6 is 4. Nothing but 4 is left for this cell.
  24. Row 2, column 5 is 4. 4 has only one place left in the top-center box.
  25. Row 1, column 2 is 4. 4 has only one place left in the top-left box.
  26. Row 3, column 3 is 1. 1 has only one place left in the top-left box.
  27. Row 2, column 2 is 8. 8 has only one place left in the top-left box.
  28. Row 1, column 6 is 1. 1 has only one place left in the top-center box.
  29. Row 2, column 6 is 5. 5 has only one place left in the top-center box.
  30. Row 6, column 2 is 1. 1 has only one place left in the middle-left box.
  31. Row 4, column 5 is 5. 5 has only one place left in the center box.
  32. Row 4, column 4 is 1. 1 has only one place left in the center box.
  33. Row 7, column 5 is 1. 1 has only one place left in the bottom-center box.
  34. Row 7, column 6 is 6. 6 has only one place left in the bottom-center box.
  35. Row 6, column 5 is 6. 6 has only one place left in the center box.
  36. Row 9, column 4 is 8. 8 has only one place left in the bottom-center box.
  37. Row 3, column 5 is 8. 8 has only one place left in the top-center box.
  38. Row 3, column 4 is 2. 2 has only one place left in the top-center box.
  39. Row 5, column 5 is 2. 2 has only one place left in the center box.
  40. Row 7, column 1 is 8. 8 has only one place left in the bottom-left box.
  41. Row 8, column 1 is 9. 9 has only one place left in the bottom-left box.
  42. Row 9, column 1 is 1. 1 has only one place left in the bottom-left box.
  43. Row 8, column 8 is 1. 1 has only one place left in the bottom-right box.
  44. Row 5, column 9 is 1. 1 has only one place left in the middle-right box.
  45. Row 6, column 7 is 9. 9 has only one place left in the middle-right box.
  46. Row 5, column 4 is 9. 9 has only one place left in the center box.
  47. Row 6, column 4 is 7. 7 has only one place left in the center box.
  48. Row 4, column 3 is 7. 7 has only one place left in the middle-left box.
  49. Row 6, column 3 is 8. 8 has only one place left in the middle-left box.
  50. Row 4, column 6 is 8. 8 has only one place left in the center box.
  51. Row 6, column 6 is 3. 3 has only one place left in the center box.
  52. Row 4, column 7 is 3. 3 has only one place left in the middle-right box.
  53. Row 5, column 8 is 7. 7 has only one place left in the middle-right box.
  54. Row 8, column 7 is 7. 7 has only one place left in the bottom-right box.
  55. Row 7, column 9 is 9. 9 has only one place left in the bottom-right box.

Hard — 30 digits given

Beyond singles, this board asks for a pointing line, a claimed box and an XY-wing.

The board

· · · | · · · | 6 1 ·
5 1 4 | · · 8 | · · ·
· · · | · 7 2 | 3 · ·
------+-------+------
6 · · | · 4 · | 5 7 ·
· · 3 | 5 · 7 | 9 · ·
· 7 5 | · 2 · | · · 3
------+-------+------
· · 2 | 9 5 · | · · ·
· · · | 2 · · | 4 9 6
· 6 9 | · · · | · · ·

The solution

2 3 7 | 4 9 5 | 6 1 8
5 1 4 | 3 6 8 | 7 2 9
9 8 6 | 1 7 2 | 3 4 5
------+-------+------
6 9 1 | 8 4 3 | 5 7 2
8 2 3 | 5 1 7 | 9 6 4
4 7 5 | 6 2 9 | 1 8 3
------+-------+------
1 4 2 | 9 5 6 | 8 3 7
7 5 8 | 2 3 1 | 4 9 6
3 6 9 | 7 8 4 | 2 5 1

A path through it

The order a solver takes — always the cheapest move left, so a pattern is only reached for when the singles run dry. 54 steps; yours need not match, and any order that never guesses ends on the same grid.

  1. Row 3, column 3 is 6. 6 has only one place left in the top-left box.
  2. Row 3, column 4 is 1. 1 has only one place left in the top-center box.
  3. Row 1, column 6 is 5. 5 has only one place left in the top-center box.
  4. Row 1, column 4 is 4. 4 has only one place left in the top-center box.
  5. Row 8, column 2 is 5. 5 has only one place left in the bottom-left box.
  6. Row 7, column 6 is 6. 6 has only one place left in the bottom-center box.
  7. Row 9, column 6 is 4. 4 has only one place left in the bottom-center box.
  8. Row 9, column 4 is 7. 7 has only one place left in the bottom-center box.
  9. Row 2, column 8 is 2. Nothing but 2 is left for this cell.
  10. Row 9, column 7 is 2. 2 has only one place left in column 7.
  11. Row 2, column 7 is 7. Nothing but 7 is left for this cell.
  12. Row 7, column 9 is 7. 7 has only one place left in the bottom-right box.
  13. Row 2, column 9 is 9. Nothing but 9 is left for this cell.
  14. Row 1, column 5 is 9. 9 has only one place left in the top-center box.
  15. Row 1, column 9 is 8. Nothing but 8 is left for this cell.
  16. Row 1, column 3 is 7. Nothing but 7 is left for this cell.
  17. Row 8, column 1 is 7. 7 has only one place left in the bottom-left box.
  18. In the bottom-center box, 8 can only sit in column 5, so it leaves the rest of that column.
  19. In row 8, 3 can only sit inside the bottom-center box, so it leaves the rest of that box.
  20. XY-wing: one of its two wings must be 1, so no cell that sees both can be.
  21. Row 6, column 6 is 9. Nothing but 9 is left for this cell.
  22. Row 4, column 2 is 9. 9 has only one place left in the middle-left box.
  23. Row 3, column 1 is 9. 9 has only one place left in the top-left box.
  24. Row 3, column 2 is 8. 8 has only one place left in the top-left box.
  25. Row 4, column 9 is 2. 2 has only one place left in row 4.
  26. Row 6, column 7 is 1. 1 has only one place left in the middle-right box.
  27. Row 9, column 9 is 1. 1 has only one place left in the bottom-right box.
  28. Row 9, column 8 is 5. 5 has only one place left in the bottom-right box.
  29. Row 3, column 9 is 5. 5 has only one place left in the top-right box.
  30. Row 3, column 8 is 4. 4 has only one place left in the top-right box.
  31. Row 5, column 9 is 4. 4 has only one place left in the middle-right box.
  32. Row 6, column 1 is 4. 4 has only one place left in the middle-left box.
  33. Row 7, column 2 is 4. 4 has only one place left in the bottom-left box.
  34. Row 7, column 8 is 3. 3 has only one place left in the bottom-right box.
  35. Row 9, column 1 is 3. 3 has only one place left in the bottom-left box.
  36. Row 1, column 2 is 3. 3 has only one place left in the top-left box.
  37. Row 1, column 1 is 2. 2 has only one place left in the top-left box.
  38. Row 5, column 2 is 2. 2 has only one place left in the middle-left box.
  39. Row 7, column 7 is 8. 8 has only one place left in the bottom-right box.
  40. Row 8, column 3 is 8. 8 has only one place left in the bottom-left box.
  41. Row 5, column 1 is 8. 8 has only one place left in the middle-left box.
  42. Row 4, column 3 is 1. 1 has only one place left in the middle-left box.
  43. Row 5, column 5 is 1. 1 has only one place left in the center box.
  44. Row 6, column 4 is 6. 6 has only one place left in the center box.
  45. Row 2, column 5 is 6. 6 has only one place left in the top-center box.
  46. Row 2, column 4 is 3. 3 has only one place left in the top-center box.
  47. Row 4, column 6 is 3. 3 has only one place left in the center box.
  48. Row 4, column 4 is 8. 8 has only one place left in the center box.
  49. Row 5, column 8 is 6. 6 has only one place left in the middle-right box.
  50. Row 6, column 8 is 8. 8 has only one place left in the middle-right box.
  51. Row 7, column 1 is 1. 1 has only one place left in the bottom-left box.
  52. Row 8, column 6 is 1. 1 has only one place left in the bottom-center box.
  53. Row 8, column 5 is 3. 3 has only one place left in the bottom-center box.
  54. Row 9, column 5 is 8. 8 has only one place left in the bottom-center box.

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About Sudoku

Sudoku on Noggin is three boards a day, on the second shelf: every entry is checked at once, a hint fills the next cell a solver would and says why, and the first board finished is the day’s score, outside the daily line-up. How to play Sudoku, or play today’s.