Hard 9x9 Calcudoku Puzzles by krazydad, 1-per-page Each booklet contains a collection of 8 different puzzles, with the answers in the back.

Free printable and interactive sudoku, mazes, and logic puzzles.

Free printable and interactive sudoku, mazes, and logic puzzles.

Free printable and interactive sudoku, mazes, and logic puzzles.

5x Calcudoku Puzzles by krazydad Each booklet contains a collection of 12 different puzzles, with the answers in the back.

Area 51 Puzzles by krazydad, Volume 1 Here are hundreds of free Area 51 puzzles suitable for printing. Area 51 is a Slitherlink variant invented by David Millar. Along with Slitherlink, it also shares rules …

Medium 5x Calcudoku Puzzles by krazydad Each booklet contains a collection of 12 different puzzles, with the answers in the back.