《数学新课程标准》指出:“教师教学应该以学生的认知发展水平和已有的经验为基础,面向全体学生,注重启发式和因材施教。”学情研究,是一种以教材内容为基础,运用调查研究方法对学生已有的认知水平、知识基础、学习技能、生活经验等进行的,用以帮助教师科学合理地设计教学,组织教学提供依据的课前研究。课堂教学是教学最基本的形式,教学的有效是所有教育者共同的追求,如何实施有效教学、构建有效课堂成为当前 The New Curriculum Standard for Mathematics states that: “Teachers’ teaching should be based on the level of cognitive development of students and the existing experience, be aimed at all students, be heuristic and be taught in accordance with their aptitudes.” " Based on the use of research methods to students’ existing cognitive level, knowledge base, learning skills, life experience and so on, to help teachers design a scientific and rational teaching, organize teaching to provide the basis for pre-study. Classroom teaching is the most basic form of teaching. The effective teaching is the common pursuit of all educators. How to implement effective teaching and how to construct an effective classroom become the current