Wang Chaoxia's paper is three or four stars difficult. Wang Chaoxia Peiyou 100 mark: RJ difficulty in mathematics in grade three: we should not only pay attention to key knowledge, but also properly examine the coverage of knowledge. Test both double basics and various abilities. Knowledge distribution is reasonable and all levels are easy to match. It has good reliability, validity, difficulty and discrimination, and can accurately test the authenticity of students' mastery and application of what they have learned. Really keep pace with the times.