Good foundation. Beijing Normal University Mathematics Green Card of China Normal University Edition is suitable in difficulty, detailed in analysis, closely related to class hours, helping students to practice by themselves without obstacles, and truly "taking notes" helps you to have a smooth knowledge. The green card of Beijing Normal University is still suitable for children with good foundation. If the foundation is not good, brush the questions with primary school. The mathematics green card of Beijing Normal University is equipped with a series of teaching AIDS for all subjects and grades from primary school to junior high school.