当今社会,孩子们的零花钱很多,从来都不计划口袋中钱如何花,更别说怎样用节省、省了多少。然而课本知识与生活实践相撞时,便无处下手了。比如在现行北师大版数学教材九年级上册第二章“一元二次方程的应用”中的利润类问题就是学生比较头疼的问题,他们往往因为缺乏生活经验、不理解在具体情境中经济利润类问题中的数量关系,在历年中考和期末考试中对这类问题束手无策、出错率极高。此类利润问题的应用题是比较 In today’s society, children have a lot of pocket money. They never plan how to spend money in their pockets, let alone how to save money and how much they save. However, when textbook collide with life practice, we have nowhere to start. For example, in the current Beijing Normal University version of mathematics textbooks on the ninth grade on the second chapter “one quadratic equation application ” in the profit class is a problem for students more headaches, they often because of the lack of life experience, do not understand in specific contexts The relationship between economic profit and the quantity of such problems is extremely troublesome and has a very high rate of error in mid-term exams and final exams. The application of such a profit issue is a comparison