Fun & Simple Smart Electronic Sudoku Game with One Billion Puzzles for Ages 6-106! Sudoku has taken the world by storm, becoming massively popular with people of all ages Challenge your Sudoku skills with this smart electronic premium Sudoku game - it's easy, simple and fun to use! Contains over 1 billion puzzles with 9 difficulty levels, has hint & solve features, cell memory function, sound on/off and loads more Insert your own puzzles from magazines or purchase 2 machines & use the "Match" button to play against a friend Requires 3 X AAA batteries (included). Suitable for ages 6 and over.