比和比例是小学数学教学中的重点之一。教学目的是使学生掌握比和比例、正比例和反比例的概念及基本性质,能够正确判断两种相关的量能否成比例关系,成什么样的比例,着重培养学生正确、熟练地解答正、反比例应用题的能力。一、比和比例的概念讲解比时要联系除法、分数、一个数是另一个数的几倍或几分之几等概念,使学生知道两数相除 Ratio and ratio is one of the key points in elementary mathematics teaching. The purpose of teaching is to enable students to master the concepts and basic properties of proportionality, proportionality and inverse proportion, and to correctly judge whether the two related quantities can be in a proportional relationship or not. What kind of proportion should be given to the students so that students can correctly and skillfully answer positive and inverse proportion Ability to apply the question. First, the concept of proportion and ratio to explain than when the division, the score, a number is another several times or a few minutes and other concepts, so that students know the difference between the two numbers