一、背景介绍人教版八年级下册第16章的学习内容是《分式》,教科书中从引言开始安排了大量实际问题,一方面要体现同研究分数一样,研究分式同样也是实际需要,另一方面是体现数学建模思想,加强学生应用数学知识于实际的兴趣和意识.其中§16.2.1节的主要内容是 First, the background introduction PEP eighth graders Chapter 16 of the learning content is “fractional”, textbooks from the introduction began to arrange a large number of practical problems, on the one hand to reflect with the same as the research scores, the research division is also the actual needs , On the other hand, it embodies the idea of ​​mathematical modeling and strengthens students’ practical interest and consciousness in applying mathematical knowledge. The main contents of §16.2.1 are