Hard Sudoku Puzzles (Set 2)
Hard Sudoku Puzzles (Set 2): free printable sudoku puzzles with an answer key. Fill every row, column and 3x3 box with the numbers 1 to 9. No guessing needed, but you will have to think! Great for ages 10 and up, early finishers and math centers.
- Size
- US Letter (8.5 × 11 in), fits A4
- 2 pages: the puzzle and its answer key
- Level
- Hard
- License
- Free for personal & classroom use
About this puzzle
Free printable sudoku puzzles with an answer key. Fill every row, column and 3x3 box with the numbers 1 to 9. No guessing needed, but you will have to think! Take your time: every hard puzzle is solvable by logic alone. Start with the row, column or box that has the most numbers filled in.
On this sheet
2 puzzles: puzzle 1 starts with 27 given numbers (2 9 9 1 8 5 6 9 4 6 7 4 ...); puzzle 2 starts with 25 given numbers (6 5 9 9 7 9 4 6 9 3 2 1 ...).
Tips for using it
- Write small pencil notes in the corners when two numbers could fit.
- Start with the easiest clue or the fullest row, column or box.
- Never guess: if you are stuck, look for one more thing you know for sure.
- Use a pencil and keep an eraser handy.
Printing tips
Download the PDF and print at 100% (or “fit to page” on A4). Page 1 is the puzzle and page 2 is the answer key with the answers in red; print just page 1 if you want to keep the answers for checking. The PNG shows page 1 only. Free for personal, family and classroom use.
