Su Doku - the completely compulsive number-placing puzzle.
Everyone can enjoy Su Doku puzzles. You don't need to be a mathematical genius, nor do you have to be good at mental arithmetic. The fact is that Su Doku puzzles are really logic puzzles that happen to use numbers - you solve the puzzles by reasoning, not calculation.
All you do is fill in the grid so that every row, every column, and every 3x3 box contains the numbers 1 through to 9. That's all there is to it... and there's only one solution to each puzzle.
Now here is the book, arranged in increasing order of difficulty, from easiest 'mini Su Doku' puzzles right up to the new 'Super Su Doku'.
Su Doku - guaranteed addiction.