一、对教材“拉一拉”的疑惑课改已经多年,在教学三角形的认识一课中,关于三角形稳定性的教学,人教版教材如图设计,我们教师大多也是这么教学的,常常让学生来拉一拉“学具”(往往是塑料做的),而这种做法会常常出现意外,会出现有学生将其“拉断”的情况,导致学生对“三角形的稳定性”产生了疑问,甚至有学生认为他的“三角形”是不稳定的,笔者记得编者早在2006年第5期杨兴放老师的《钉成四边形木框也不变形》一文编者语中,已经详细 First, the textbook “pull a pull” doubts Curriculum has changed for many years, teaching a triangle in a lesson about the teaching of the stability of the triangle, the PEP textbook design, most of our teachers are so teaching, Often let students pull a “learning” (often made of plastic), and this practice will often be unexpected, there will be students to “pull off” the situation, leading students to “ The stability of the triangle ”have a doubt, and even some students think his “ triangle ”is not stable, I remember the editor as early as in 2006 No. 5 Yang Xing Fang teacher“ nail into a quadrilateral wooden frame is not deformed, ”a text Editor’s language, has been detailed