Akira Electronic Sudoku Number Puzzle Handheld Travel Game with Keypad - 4.5 Inch
Sudoku is a logic-based number placement puzzle. The objective is to fill a 99 grid so that each column, each row, and each of the nine 33 boxes (also called blocks or regions) contains the digits from 1 to 9 only one time each. The puzzle setter provides a partially completed grid.