a number puzzle with nine squares, each containing nine smaller squares, in which you have to put the numbers one to nine so that a number appears only once in each of the nine squares and in each row of nine across and down the puzzle 數獨遊戲(九個大方格中各有九個小方格,要求在空格中填數字一到九,且縱、橫排各不重複) He passes the time doing sudokus. 他做數獨遊戲打發時間。 There are sudokus at four levels of difficulty. 有四個難度級别的數獨。