Mathematics for the first grade of primary school, the second volume of the exercise book of People's Education Edition; You shoot one, I shoot one, and a star has five angles; You shoot two, I shoot two, two stars 10 angle; You shoot three, I shoot three, Samsung 15 angle; You shoot four, I shoot four, four stars, 20 horns; You shoot five, I shoot five, five stars and 25 cents. . . I think so too. .