Scanning is especially effective when you’re looking at both rows and columns at the same time.

The goal is to look at all the boxes where the number can’t be placed, hopefully leaving the one box where it should be. This involves picking a number and then looking at rows and columns across the grid containing that number. The most basic technique for solving free online Sudoku is to use the scanning method. Of course, free online Sudoku that can be played at any time of day soon followed. Sudoku quickly spread to newspapers all over the world, delighting users every single day. Sudoku games were introduced in Japan five years later, where the number puzzles became immensely popular and were officially coined 'Sudoku.' In 2004, The Times in London published its first daily Sudoku, reintroducing the Sudoku puzzle to Western culture. His Sudoku used a 9x9 square, and all rows and columns needed to contain the numbers 1-9. These number puzzles disappeared around World War I, but reemerged in 1979 when an Indiana man named Howard Garns published the first modern Sudoku puzzle. The rows and columns did, though, add up to the same number. The number puzzles were not the exact same as sudoku, though, because they contained some double-digit numbers and did not have sub-squares. Number puzzles became popular in the late 1800s in France, when newspapers began to publish partially-filled number grids on their pages. Additionally, the puzzle is updated every day giving you a new Sudoku challenge each and every day! Sudoku History We offer Sudoku for beginners, medium Sudoku, and Sudoku for experts. Our free online version of web Sudoku follows in the number puzzle's classic tradition, no pen or pencil needed! As you start the puzzle you can choose your Sudoku difficulty. Think you have what it takes? About Sudoku While free online Sudoku can be rather challenging, the rules and general game play are pretty simple and straightforward.Įach column, row and nonet needs to contain the numbers 1-9, and each number can only be used once.

Easy sudoku free printable