北师大七年级数学教材中有一节“字母能表示什么 ?”其中创设了一个问题情景 ,以此作为课程内容的引入 (详见课本 ) .初看到这样的问题情境 ,确实让人耳目一新 .而在传统的数学课堂中 ,老师会直接告诉学生 :“字母可以表示任何数” .作为学生来说 ,他们只要毫无怀疑的接受就行? The seventh grade mathematics textbooks in Beijing Normal University, a section of “letters can show what?” Which created a problem scenario, as the introduction of the course content (see textbook). At first sight of such a problem situation, really refreshing In traditional math classes, however, the teacher tells students directly: “Letters can mean any number.” As students, they are accepted without any doubt.