Here's the ultimate treat for all fans of the number-placement puzzle sudoku: a mega collection of 1000 grids arranged by level of difficulty. This compilation will satisfy both ardent puzzle enthusiasts and beginners looking to test their skill.
Eric Saunders is a prolific writer of non-fiction for children and adults, specialising in puzzle and activity books. He has been compiling puzzles for over 35 years, and his work can be found in books, newspapers and websites around the world. He lives in Wales.