Practice and check
Worked example
Check one empty cell against its row, column, and 3×3 box. Only a candidate allowed by all three may be written.
Row 5, Column 5: {1,2,3,4,5,6,7,8,9} − {2,3,4,5,6,7,8,9} = {1}
- Row 5, Column 5
- {1,2,3,4,5,6,7,8,9} − {2,3,4,5,6,7,8,9} = {1}
Check answers after trying
1: 1 6 8 3 5 7 9 2 4 2: 3 5 4 2 9 1 6 8 7 3: 2 9 7 6 8 4 1 3 5 4: 7 1 9 5 3 2 8 4 6 5: 8 4 3 7 1 6 5 9 2 6: 5 2 6 9 4 8 7 1 3 7: 9 3 2 1 6 5 4 7 8 8: 4 7 5 8 2 9 3 6 1 9: 6 8 1 4 7 3 2 5 9
Printed order
Tips for Parents
▸ What is on the sheet undefined A–C repeat the same blank positions with different digits. A–D are practice-set names, not ranked difficulty. Given cells: 30; Empty cells: 51. ▸ Try one example Row 5, Column 5: {1,2,3,4,5,6,7,8,9} − {2,3,4,5,6,7,8,9} = {1} ▸ Check a difficulty Check one empty cell against its row, column, and 3×3 box. Only a candidate allowed by all three may be written. ▸ Choose the next step Sudoku - 9×9 · Practice Set A / B / C / D. A–C repeat the same blank positions with different digits. A–D are practice-set names, not ranked difficulty.
What This Worksheet Builds
Check one empty cell against its row, column, and 3×3 box. Only a candidate allowed by all three may be written.
Next Step
Sudoku - 9×9 · Practice Set A / B / C / D. A–C repeat the same blank positions with different digits. A–D are practice-set names, not ranked difficulty.