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Sudoku #38 — the solutions

The three Sudoku boards from November 7, 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

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

The solution

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

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

Medium — 28 digits given

Beyond singles, this board asks for a naked pair.

The board

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

The solution

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

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 2 is 4. 4 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 3, column 5 is 8. 8 has only one place left in the top-center box.
  4. Row 3, column 4 is 1. 1 has only one place left in the top-center box.
  5. Row 1, column 4 is 5. 5 has only one place left in the top-center box.
  6. Row 1, column 8 is 7. 7 has only one place left in the top-right box.
  7. Row 2, column 8 is 6. 6 has only one place left in the top-right box.
  8. Row 1, column 1 is 6. 6 has only one place left in the top-left box.
  9. Row 2, column 7 is 1. 1 has only one place left in the top-right box.
  10. Row 1, column 7 is 2. 2 has only one place left in the top-right box.
  11. Row 2, column 6 is 2. 2 has only one place left in the top-center box.
  12. Row 6, column 6 is 7. 7 has only one place left in the center box.
  13. Row 9, column 6 is 8. 8 has only one place left in the bottom-center box.
  14. Row 8, column 3 is 8. 8 has only one place left in the bottom-left box.
  15. Row 9, column 3 is 7. 7 has only one place left in the bottom-left box.
  16. Row 8, column 9 is 7. 7 has only one place left in the bottom-right box.
  17. Row 3, column 7 is 5. 5 has only one place left in column 7.
  18. Row 3, column 8 is 3. 3 has only one place left in the top-right box.
  19. Row 3, column 9 is 9. 9 has only one place left in the top-right box.
  20. Row 5, column 7 is 3. 3 has only one place left in the middle-right box.
  21. Row 6, column 8 is 4. 4 has only one place left in the middle-right box.
  22. Row 8, column 7 is 4. 4 has only one place left in the bottom-right box.
  23. Row 2, column 3 is 3. 3 has only one place left in column 3.
  24. Row 1, column 6 is 3. 3 has only one place left in column 6.
  25. Row 1, column 5 is 9. 9 has only one place left in the top-center box.
  26. Two cells in column 5 hold only 2 and 3, so no other cell there can.
  27. Row 4, column 5 is 1. Nothing but 1 is left for this cell.
  28. Row 5, column 9 is 1. 1 has only one place left in the middle-right box.
  29. Row 4, column 8 is 2. 2 has only one place left in the middle-right box.
  30. Row 9, column 9 is 2. 2 has only one place left in the bottom-right box.
  31. Row 8, column 4 is 2. 2 has only one place left in the bottom-center box.
  32. Row 6, column 5 is 2. 2 has only one place left in the center box.
  33. Row 5, column 1 is 2. 2 has only one place left in the middle-left box.
  34. Row 5, column 3 is 5. 5 has only one place left in the middle-left box.
  35. Row 4, column 2 is 9. 9 has only one place left in the middle-left box.
  36. Row 2, column 1 is 9. 9 has only one place left in the top-left box.
  37. Row 2, column 2 is 5. 5 has only one place left in the top-left box.
  38. Row 6, column 2 is 3. 3 has only one place left in the middle-left box.
  39. Row 4, column 4 is 3. 3 has only one place left in the center box.
  40. Row 7, column 2 is 2. 2 has only one place left in the bottom-left box.
  41. Row 9, column 2 is 1. 1 has only one place left in the bottom-left box.
  42. Row 7, column 1 is 5. 5 has only one place left in the bottom-left box.
  43. Row 8, column 2 is 6. 6 has only one place left in the bottom-left box.
  44. Row 7, column 3 is 9. 9 has only one place left in the bottom-left box.
  45. Row 9, column 5 is 3. 3 has only one place left in the bottom-center box.
  46. Row 7, column 5 is 6. 6 has only one place left in the bottom-center box.
  47. Row 5, column 4 is 6. 6 has only one place left in the center box.
  48. Row 5, column 6 is 9. 9 has only one place left in the center box.
  49. Row 5, column 5 is 4. 4 has only one place left in the center box.
  50. Row 7, column 6 is 4. 4 has only one place left in the bottom-center box.
  51. Row 9, column 4 is 9. 9 has only one place left in the bottom-center box.
  52. Row 7, column 8 is 1. 1 has only one place left in the bottom-right box.
  53. Row 9, column 8 is 5. 5 has only one place left in the bottom-right box.
  54. Row 8, column 8 is 9. 9 has only one place left in the bottom-right box.

Hard — 27 digits given

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

The board

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

The solution

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

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. 56 steps; yours need not match, and any order that never guesses ends on the same grid.

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