The puzzle is most frequently a 9×9 grid, made up of 3×3 subgrids called "regions" (other terms include "boxes", "blocks", and the like when referring to the standard variation; even "quadrants" is sometimes used, despite this being an inaccurate term for a 9×9 grid). Some cells already contain numerals, known as "givens" (or sometimes as "clues"). The goal is to fill in the empty cells, one numeral in each, so that each column, row, and region contains the numerals 1–9 exactly once. Each numeral in the solution therefore occurs only once in each of three "directions" or "scopes", hence the "single numbers" implied by the puzzle's name.
That's all there is to it. There's no math involved. The grid has numbers, but nothing has to add up to anything else. You solve the puzzle with reasoning and logic.
It's fun. It's challenging. It's addictive!
Solving time is typically
from 10 to 30 minutes,
depending on your skill and experience
The name Sudoku is the Japanese abbreviation of a longer phrase, "suuji wa dokushin ni kagiru" meaning "the digits must remain single"; Online Soduko trademark of puzzle publisher Nikoli Co. Ltd in Japan. In Japanese, the word is pronounced Sudoku; in English Soduko and in hebrew ?????? .Other Japanese publishers refer to the puzzle as Number Place, the original U. S. title, or as "Nanpure" for short. Some non-Japanese publishers spell the title as "Su Doku".