The Sudoku challenge

Sudoku is the simple number puzzle that has swept the world and obsessed millions of puzzlers of all ages. It takes no mathematical knowledge and you don't need a large vocabulary. All it takes is a pencil and some logic. In this compilation there are 200 puzzles ranging from 'nice and easy' to 'fiendishly difficult'. From simple puzzles a nine-year-old could complete to megasudoku grids of 25 X 25, work through the book to become a master puzzler. The pocket-book format means that you can work on a Sudoku anywhere - whilst commuting, on the beach, or on a lunch break.