Sudoku
Sudoku (数独) is a logic-based, combinatorial number-placement puzzle. The objective is to fill a 9 × 9 grid with digits so that each column, each row, and each of the nine 3 × 3 subgrids contain all of the digits from 1 to 9. A well-posed puzzle has a single solution.
Number puzzles appeared in French newspapers in the late 19th century, but most of these required arithmetic rather than logic to solve.
It is believed that the modern Sudoku was 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 modern Sudoku gained popularity in 1986 when it was published by the Japanese puzzle company Nikoli under the name Sudoku, meaning "single number". It first appeared in a U.S. newspaper, and then The Times in London.
Sudoku involved an area of cognition called working memory. Routine Sudoku playing could improve working memory in older people.
There are now many variants. I have played a few of these variants, but I like the 3D Sudoku most. The 3D Sudoku itself has a few sub-variants. My daughter sent me four years ago at Christmas from San Francisco the first 3D Sudoku book, and now 3D Sudoku can be ordered online.
Sudoku
Sudoku (数独) is a logic-based, combinatorial number-placement puzzle. The objective is to fill a 9 × 9 grid with digits so that each column, each row, and each of the nine 3 × 3 subgrids contain all of the digits from 1 to 9. A well-posed puzzle has a single solution.
Number puzzles appeared in French newspapers in the late 19th century, but most of these required arithmetic rather than logic to solve.
It is believed that the modern Sudoku was 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 modern Sudoku gained popularity in 1986 when it was published by the Japanese puzzle company Nikoli under the name Sudoku, meaning "single number". It first appeared in a U.S. newspaper, and then The Times in London.
Sudoku involved an area of cognition called working memory. Routine Sudoku playing could improve working memory in older people.
There are now many variants. I have played a few of these variants, but I like the 3D Sudoku most. The 3D Sudoku itself has a few sub-variants. My daughter sent me four years ago at Christmas from San Francisco the first 3D Sudoku book, and now 3D Sudoku can be ordered online.