我们都知道，学生学习数学知识的过程，是一个以积极的心态调动原有的知识、经验，尝试解决新问题、同化新知识的积极建构的过程。这个过程必须靠学生自己来完成。教师的作用在于充分发挥其主导作用，即由演员变成导演，把表演的权利还给学生。为此，在课堂教学中要灵活选用教 We all know that the process of students' learning of mathematical knowledge is a positive process of mobilizing the original knowledge and experience, trying to solve new problems and assimilating new knowledge with a positive attitude. This process must be done by the students themselves. The teacher's role is to give full play to its leading role, that is, by the actor into a director, the performance rights back to students. To this end, in the classroom teaching should be flexible use of teaching