我市新安小学陈天林老师上“分数的基本性质”一课,精心设计教学方法,比较巧妙地帮助学生突破知识的难点,透彻地理解了新知识,收到了理想的教学效果。现摘其片断介绍如下: 上课开始,在进行有针对性的基本训练后,教者出示①3/4、6/8、9/12,②1/3,2/6、3/9两组分数,让学生比较每一组中三个分数的大小。此时学生感到不能直接比较它们的大小,无法回答这个问题。这是教者有意造成了学生认知上的冲突,可谓巧设疑难,激发思维。接着让学生拿出事先准备好的三个等圆动手折剪,分别取出各自的3/4、6/8、9/12,再要求学生将分别取出各圆的3/4、6/8、9/12部分两两重合起来,这时学生意外 Xin'an Primary School, the city Chen Tianlin teacher on the “basic nature of scores,” a lesson designed elaborate teaching methods, more skillfully to help students break through the difficulties of knowledge, a thorough understanding of the new knowledge, received the ideal teaching results. Now take the fragment introduced as follows: At the beginning of the class, after carrying out targeted basic training, the teacher showed ① 3 / 4,6 / 8,9 / 12, ② 1/3, 2/6, 3/9 two groups of scores, Have students compare the size of three points in each group. At this point students feel unable to directly compare their size, can not answer this question. This is the intention of the teacher causing the student's cognitive conflict, which can be described as setting difficulties and stimulating thinking. Then let the students come up with three ready-to-go hands-on scissors, remove their respective 3 / 4,6 / 8,9 / 12, and then asked the students to remove the respective 3 / 4,6 / 8, Part 9 and 12 together, when the students accident