【教学内容】人教版三年级上册第21、22页。【课前思考】我认为,数学学习的本质是认知改造。具体地说,学生带着已有经验进入课堂,然后充分暴露经验,不断矫正经验,持续丰富经验,有效提升经验,最终获得新知识、建构新经验。而这也成为我设计本课的指导思想。【教学过程】一、复习旧知,引出新知1.回顾旧知。 【Teaching content】 PEP third grade on the first 21, 22 pages. [Thinking before class] I think that the essence of mathematical learning is cognitive reform. Specifically, students enter the classroom with existing experience and then fully expose their experience, continuously correct their experiences, continuously enrich their experience, improve their experience effectively, and finally acquire new knowledge and construct new experiences. And this has also become my guiding ideology of this lesson. [Teaching process] First, review the old knowledge, leads to new knowledge 1. Review of the old knowledge.