600+ Sudoku Puzzles: From Easy to Hard Level

Sudoku is a fabulous brain exercise, comprising a grid with numbers that has to be completed to an exact standard. It can come in very easy formats, or ones which will test your concentration to the limits. Inside, you will find a range of 6x6 Sudoku puzzles with differing degrees of difficulty, just right for rainy days, boring evenings or long train journeys when you have some time to kill.