在学生学习了“用字母表示数”和“列方程解答应用题”以后,常用字母x表示未知数,这个“x”只能代表“数”不能代表“量”。但据我观察,有许多教师(尤其是刚参加工作的青年教师)对其并不重视,因此学生也随之出现了很多类似的错误。现举例如下,仅供研讨。错例1一位教师在讲完三角形的面积之后,出了这样一道题:一个三角形的面积是30平方分米,它的底是10分米,高是多少分米?教师在向学生讲解时 After a student learns “Letters” and “Column equations to answer questions”, the commonly used letter x means unknowns. The “x” can only represent “” ". However, as far as I can observe, many teachers (especially the young teachers who have just started their work) do not pay much attention to them. As a result, many similar mistakes have taken place. For example, the following is for discussion only. Wrong example 1 A teacher after the completion of the triangular area, came up with such a question: a triangle area is 30 square decimeters, which is the end of 10 meters, how many decimeters? Teacher to explain to students