【案例背景】《认识简单的近似数》是苏教版小学数二年级下册第四单元“认识万以内的数”中的内容,是在学生学习过万以内的数的读写和大小比较的基础上进行教学的。本节课教学把一个接近整百或整千的数用大约几百或几千来表示,让学生初步体会近似数的含义,学会用近似数描述数的大小。由于学生的年龄小,日常生活中很少有机会接触比较大的数目,对较大数目的经验积累还不够丰富,学习这一课有一定的困难。一方面由于没有生活体验,兴趣并不高;另一方 Case Background “Knowing simple approximations” is the content of the fourth unit of the second grade of the second edition of the Sujiao version, “Number of people who know the million”, which is the number of students who read and write within a few million Based on the size of the teaching. In this lesson, a few hundred or several thousand near a hundred or a thousand are used to give students a chance to understand the meaning of approximations and learn how to approximate the numbers in terms of approximations. Due to the small age of students, few opportunities in daily life come into contact with a relatively large number, and are not rich enough for a large number of experiences to accumulate. Learning this lesson has some difficulties. On the one hand, because there is no life experience, interest is not high; the other side