←
NOGGIN
Play this puzzle Play today’s Sudoku

Sudoku #30 — the solutions

The three Sudoku boards from October 30, 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

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

The solution

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

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

The board

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

The solution

1 6 5 | 8 9 2 | 7 3 4
4 9 7 | 1 5 3 | 8 2 6
8 2 3 | 6 7 4 | 9 5 1
------+-------+------
7 4 2 | 5 6 8 | 1 9 3
5 8 6 | 3 1 9 | 2 4 7
3 1 9 | 2 4 7 | 5 6 8
------+-------+------
9 5 4 | 7 8 6 | 3 1 2
6 3 8 | 9 2 1 | 4 7 5
2 7 1 | 4 3 5 | 6 8 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. 54 steps; yours need not match, and any order that never guesses ends on the same grid.

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

Hard — 28 digits given

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

The board

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

The solution

9 2 7 | 1 8 6 | 4 3 5
5 1 3 | 9 2 4 | 8 7 6
8 4 6 | 5 7 3 | 9 2 1
------+-------+------
7 3 9 | 2 1 5 | 6 8 4
4 8 5 | 7 6 9 | 2 1 3
1 6 2 | 3 4 8 | 5 9 7
------+-------+------
6 5 1 | 8 9 7 | 3 4 2
2 9 4 | 6 3 1 | 7 5 8
3 7 8 | 4 5 2 | 1 6 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. 55 steps; yours need not match, and any order that never guesses ends on the same grid.

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

Previous: Sudoku #29 (Thu, Oct 29) · Next: Sudoku #31 (Sat, Oct 31) · All Sudoku solutions

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.