Sudoku is name for a type of number-based puzzle. Solving a Sudoku puzzle
requires logic that will improve your brain power and reasoning skills. Though
it appeared first in 1970s in the USA when Dell magazine used such puzzles under
the name of number place in a section on mathematical puzzles. Then it reached
in Japan in 1980s and got the name Sudoku, which in Japanese Su means 'number'
and Doku means 'bachelor' or 'single'.