Sudoku is a logic-based, combinatoric number- placement puzzle. The objective is to fill a 9-by-9 grid with each digit appearing exactly once for each row, column, and block. How to play: 1. Hover your mouse over a sqaure, click on it, and enter the numbers from 1-9 with your number keys. 2. If you want to use mobile mode, click on the button and mobile mode will turn on. 3. Each row, column, and block must contain numbers from 1 to 4, 6, or 9, depending on grid size, without repetitions. 4. The process of elimination is the best way to decide which number goes into which square. 5. Do not try to guess the solution because Sudoku is all about using logic and reasoning. Facts about Sudoku: 1. It has been around for many years in the U.S. and other countries and was popular in Japan in the 1990s. 2. The word "sudoku" is a Japanese expression meaning "single number".
