数学来源于生活,又服务于生活,可以解决实际生活中的问题。让学生理解数学学习的目的之一就是为了学以致用。而作为应用题的教学则是实现这一目的的有效徐径之一,因为求解应用题的教学不仅能使理论联系实际,而且还可以提高分析问题与解决问题的能力。设元是列方程解应用题的第一步。恰当设元能使列方程更容易,解题更简便。常用的设元方法有直接设元和间接设元。但对于一些关系较复杂、所求问题较多时,直接设元和间接设元不易解决问题,还需要我们进行整体 Mathematics comes from life and serves life. It can solve real life problems. One of the goals of having students understand mathematics learning is to apply what they have learned. Teaching as an applied problem is one of the effective ways to achieve this goal, because solving the applied problems can not only make the theory linked to reality, but also improve the ability to analyze problems and solve problems. Suppose the first step is to solve the problem of applying equations. Properly arranging elements can make equations easier and solve questions more easily. Commonly used setting methods are direct and indirect. However, when some of the relationships are more complicated and more questions are asked, directly setting up yuan and indirectly setting up the yuan is not easy to solve the problem, but we also need to conduct overall