Universal Sudoku by Andrews McMeel Syndication
Universal Sudoku (9) is the most popular and widely played Sudoku puzzle in the world. Daily delivery keeps players coming back.
It is a puzzle that uses numbers instead of words. It's a grid of 81 squares, divided into 9 blocks of 9 squares each. Some of the squares contain a digit. The goal is to fill in the empty squares so that the digits 1 through 9 appear just once in every row, column and individual block.