9×9 Hard Mathdoku 9×9 Mathdoku Puzzles 9×9 Hard 10 puzzles available 🧩 9×9 Hard #1 B → 🧩 9×9 Hard #2 B → 🧩 9×9 Hard #3 B → 🧩 9×9 Hard #4 B → 🧩 9×9 Hard #5 B → 🧩 9×9 Hard #6 B → 🧩 9×9 Hard #7 B → 🧩 9×9 Hard #8 B → 🧩 9×9 Hard #9 B → 🧩 9×9 Hard #10 B →