一、运用反例,防错纠错实践表明:反例能不断地对知识点的本质属性进行净化,不断排除非本质属性的干扰,从而引起学生的认知冲突,以此加强学生对知识点的理解,获得正确的感知,对揭露错误有着特殊的威力。比如,“平行四边形”是两组对边互相平行的四边形。它的内涵中包含“两组对边平行”和“四边形”这两个明显的本质属性。学生认识平行四边形时,如果只注意“两组对边平行”这个属性,而 First, the use of counter-examples, error-proof error correction practice shows that: counterexamples can continue to purify the essential attributes of knowledge points, and constantly exclude the interference of non-essential attributes, thus causing students ’cognitive conflicts, so as to enhance students’ understanding of knowledge points , Get the right perception, have a special power to expose mistakes. For example, “Parallelogram ” is a set of two quadrilaterals whose sides are parallel to each other. Its connotation includes two obvious essential attributes, “parallel to two sides” and “quadrilateral”. Students know the parallelogram, if only pay attention to “two sets of parallel to the edge ” this attribute, and