【案例背景】本节课的内容是在上节课“认识线段”和一年级“比一比”单元学习了比较物体长短的基础上教学的。我在这节课的教学中,力求从学生的生活经验和已有的知识背景出发,为学生提供充分的从事数学活动和交流的机会,通过观察、操作、交流、反思等学习活动,促使学生在自主探索的过程中真正理解和掌握基本的数学知识与技能、数学思想和方法。【案例描述】一、创设情境,激趣导入师:请同学们拿出课前准备好的铅笔、小纸条、钉子等物体和 Case Background The content of this lesson is based on the comparison of the lengths of the objects learned in the previous lesson “Cognitive Segments ” with the first grade “ratio one ” unit. In my class teaching, I seek to provide students with opportunities to engage in mathematical activities and exchanges based on their life experiences and existing knowledge backgrounds. Through observation, operation, exchange and reflection, I urge students In the process of self-exploration to truly understand and master the basic mathematical knowledge and skills, mathematical ideas and methods. [Case Description] First, the creation of the situation, excitement Import division: Students are invited to come up with pre-class pencils, notes, nails and other objects and