Features: 1) Display: a) LCD screen, size 56 x 58mm b) With blue LED back light 2) Game function: a) 12 different kind of games include kakuro, sudoku and other games b) 5 levels of game play c) Auto-solve function 3) Function keys: a) Reset key b) On/off key c) Mode key d) Sound key e) Function key f) Set key g) Up/down/left/right key h) 1 to 9 number pad i) Enter key j) LED lights switch 4) Other function: 12 in 1 function including 11 another games and calendar 5) Power supply: 3 x AAA alkaline batteries (not included) 6) Rules: Kakuro puzzles resemble crosswords which use numbers instead of words. The aim of the game is to fill all the blank squares in the grid with only the number 1-9 so that the number you enter add up to the corresponding clues. When the grid is filled, the puzzle is complete