Sudoku online puzzles,easy web sudoku
The sudoku's objective is to fill the sudoku 9×9 grid with digits so that each column,each row,and each of the nine 3×3 sub-grids that compose the grid (also called "boxes","blocks","regions",or "sub-squares") contains all of the digits from 1 to 9. The puzzle setter provides a partially completed grid,which typically has a unique solution.
General info about free Sudoku online (Sudoku 9x9) and other games
Sudoku History (wikipedia)
Number puzzles appeared in French newspapers in the late 19th century,It was not a Sudoku because it contained double-digit numbers and required arithmetic rather than logic to solve. On July 6,1886,Le Siècle's rival,La France,refined the puzzle so that it was almost a modern Sudoku. According to Will Shortz,the modern Sudoku was most likely designed anonymously by Howard Garns,a 74-year-old retired architect and freelance puzzle constructor from Indiana,and first published in 1979 by Dell Magazines as Number Place (the earliest known examples of modern Sudoku). Garns' name was always present on the list of contributors in issues of Dell Pencil Puzzles and Word Games that included Number Place,and was always absent from issues that did not. He died in 1989 before getting a chance to see his creation as a worldwide phenomenon. It is unclear if Garns was familiar with any of the French newspapers listed above. The sudoku puzzles was introduced in Japan by Nikoli in the paper Monthly Nikolist in April 1984 as Suji wa dokushin ni kagiru which can be translated as "the digits must be single" or "the digits are limited to one occurrence." (In Japanese,"dokushin" means an "unmarried person".) At a later date,the name was abbreviated to Sudoku by Maki Kaji ,taking only the first kanji of compound words to form a shorter version. In 1986,Nikoli introduced two innovations: the number of givens was restricted to no more than 32,and puzzles became "symmetrical" (meaning the givens were distributed in rotationally symmetric cells). It is now published in mainstream Japanese periodicals,such as the Asahi Shimbun.
Crosswords and Sudokus can delay memory loss (telegraph.co.uk)
Researchers from Albert Einstein College of Medicine,in New York,found that performing a mental exercise twice a day could help delay the rapid memory loss associated with dementia for more than a year.
Crosswords and Sudoku’s burn up to 90 calories per hour Brain training experts confirmed today that mental exercise such as crosswords,Sudokus can burn an average of 90 calories every hour.