学生对“角”的认识更多的是基于生活中的经验,而非数学中的图形。教学时,让学生经历从具体的实物中抽象出角的过程,引导他们自然地从生活实际过渡到数学知识,建立起对角的概念的正确认识。“角”广泛存在于学生的实际生活中,通过课前调查可以发现,有些学生已经能够结合自己的学习经验画出角,有些学生认为角就是长方形和正方形上的角, Students’ awareness of “corner ” is more based on the experience of life, rather than mathematical graphics. In teaching, let the students experience the process of abstracting angles from concrete objects, guide them to naturally transition from life to mathematics, and establish a correct understanding of diagonal concepts. “Corner ” exists widely in students’ real life. Through the pre-class survey, some students have been able to draw angles based on their own learning experiences. Some students think that corners are the corners of rectangles and squares,