对课堂的预设是很有必要的,并且要尽可能使教学设计符合学生的认知规律和实际情况,使课堂教学沿着预设的轨道前进。但教学过程是随机生成的,学生的学习情况经常与预设有些差距。此时,教师应运用教学机智改变原来的教学方案以适应学生,充分挖掘学生的潜能,让师生在互动的教学过程中得到发展。 The presupposition of the classroom is necessary, and to make the teaching design as far as possible to meet the cognitive rules of students and the actual situation, so that classroom teaching along the track orbit. However, the teaching process is randomly generated, and students often have some learning differences with the default. At this point, teachers should use teaching tactics to change the original teaching program to adapt to students, to fully tap the potential of students so that teachers and students in the interactive teaching process developed.