How to Solve 9x9 Sudoku for Kids
Ready to move on from 6x6 Sudoku? Classic 9x9 uses 1 through 9 once in every row, column and 3-by-3 box. The thick lines divide the grid into nine boxes. You do not need to add the numbers.
Write candidates, then check
This original mini-example is not a published worksheet or its answer. There is one empty cell in the top-left box: row 3, column 3. On a harder puzzle, pencil possible digits beside an empty cell and cross them out as its row, column or box rules them out. Do not guess.
- Which digit from 1-9 is missing in the top-left 3-by-3 box?
- Does that digit already appear elsewhere in row 3 or column 3?
One box, one missing digit
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |
| 4 | 5 | 6 | 7 | 8 | 9 | 1 | 2 | 3 |
| 7 | 8 | ? | 1 | 2 | 3 | 4 | 5 | 6 |
| 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 1 |
| 5 | 6 | 7 | 8 | 9 | 1 | 2 | 3 | 4 |
| 8 | 9 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
| 3 | 4 | 5 | 6 | 7 | 8 | 9 | 1 | 2 |
| 6 | 7 | 8 | 9 | 1 | 2 | 3 | 4 | 5 |
| 9 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 |
| 4 | 5 | 6 | 7 | 8 | 9 | 1 | 2 | 3 |
| 7 | 8 | 9 | 1 | 2 | 3 | 4 | 5 | 6 |
| 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 1 |
| 5 | 6 | 7 | 8 | 9 | 1 | 2 | 3 | 4 |
| 8 | 9 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
| 3 | 4 | 5 | 6 | 7 | 8 | 9 | 1 | 2 |
| 6 | 7 | 8 | 9 | 1 | 2 | 3 | 4 | 5 |
| 9 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
Pencil at row 3, column 3: 1, 2, 3, 4, 5, 6, 7, 8, 9. The box rules out the crossed-off digits; the row and column confirm 9.
- Box candidates: the top-left box has 1, 2, 3, 4, 5, 6, 7 and 8. Cross them off the 1-9 candidate list; only 9 remains.
- Cross-check: row 3 has 7, 8, 1, 2, 3, 4, 5 and 6. Column 3 has 3, 6, 4, 7, 1, 8, 5 and 2. Neither has a 9, so write 9 at row 3, column 3. Check that every row, column and box has 1-9 once.
Try a real 9x9 puzzle
Browse the 9x9 Sudoku collection or try Easy 9x9 Sudoku 1. Its printable sheet includes an adult answer key; keep that page aside while a child solves. For a smaller start, use the 4x4 beginner guide, or return to all Sudoku puzzles.