“认识角”是北师大版教材二年级下册“认识图形”单元中的第一节课,安排了两个课时的教学内容。教材按照“画一画”“认一认”“标一标”“比一比”的编排思路帮助学生在活动中建立角的表象,我觉得很合理。但是,如何选择学习材料、组织数学活动呢?如何引导学生在活动后反思,在反思中更深刻、更立体地体验角呢?我思考后,为本课确定了以下教学目标:1.在“找一找”的活动中,体验面在体上、角在面上,并初步建立角的表象。2.在“画一画”的活动中,经历尝试、比较、辨析的过程,进一步体验角的意义。3.在“做一做”的活动中,经历观 “Recognition angle ” is the first lesson of the second grade under the Beijing Normal University Edition teaching materials “understanding figure ” unit, arranged for two hours of teaching content. Teaching materials in accordance with “draw a picture ” “recognize a recognition ” “standard ” “than a ratio ” arrangement train of thought to help students in the activity to establish the appearance of the corner, I find it very reasonable. However, how to choose to study materials, organize mathematical activities? How to guide students to reflect on the activities, in the reflection of a deeper and more three-dimensional experience of the angle? After I thought, the following teaching objectives for the lesson: 1. In “Find One” activities, the experience surface is on the body, the angle is on the surface, and the initial appearance of the corner is established. 2. In the “draw a picture” activities, through trial, comparison, analysis of the process, to further experience the meaning of the corner. In the “do one ” activities, experience the concept