Green Sudoku easy to operate!

300 Sudoku you can play for free! A popular Sudoku in the world as a pencil puzzle, it will play free of charge 400 questions! Let's train the brain! Easy to operate! It is easier to operate than other Sudoku apps! 9 Mass buttons are easy to push. When you press a long press to enter numbers immediately, It has undo, redo function, copy and paste functions.