Feed me more numbers - now! It's crunching time
Yesterday I did not know what a su doku (or sudoku) was. Today I can see myself easily hooked on the latest craze in number puzzles in less time than it would take you to say 'compulsive-obsessive personality disorder'.
Simple ideas are often the best: a nine-by-nine grid, where each of the nine rows must contain all figures from one to nine, as must each of the nine columns, and each of the nine squares contained in it.
According to the number and quality of the clues, it can be disappointingly easy or fiendishly difficult. The better quality grids have symmetrical clues and only one possible solution.