在小学数学教材中关于正比例意义的学习是小学数学中渗透函数思想一个重要内容。学生最难理解的是两个量之间的变化关系,两个量之间为什么一定要建立比的关系,建立比的关系时所得的第三量与已知两个量之间有什么关系;还有的学生感到困惑的是已知两个量怎么样才能建立比的关系,建立比的关系有什么标准,是不是两个量之间一定要建立比的关系才能判断两个量之间存在正比例关系。在下面的教学中,我们借助多媒体一步一步地引导学生, In primary school mathematics textbooks about the proportion of learning is an important part of elementary school mathematics thought of infiltration function. The most difficult for students to understand is the relationship between the two variables, why the two must be established between the ratio of the relationship between the establishment of the relationship between the third volume and the two known amount of what is the relationship between; There are students who are confused about how to establish the relationship between the two quantities, the establishment of the relationship between the ratio of what is the relationship between the two quantities must be established to determine the ratio between the two quantities Proportionality. In the following teaching, we use multimedia to guide students step by step,