教学过程是一个动态的变化过程 ,随时会碰到意料不到的情况 ,学生的思路也很难与教师备课时设计的方案完全吻合。当学生出现错误时 ,教师切忌急躁、反感 ,而应机智灵活地控制和调节教学的难度和进度。步步进逼、设疑激趣、解惑益智是化错为正的有效方法。如 ,教学三角形的概念 Teaching process is a dynamic process of change, at any time will encounter unexpected situations, students' thinking is also very difficult with the teacher designed lesson plan completely consistent. When a student goes wrong, the teacher should not be impatient and disgusted, but should be smart and flexible in controlling and adjusting the difficulty and progress of teaching. Step by step, set doubts doubt, puzzle is a valid method of error is positive. For example, the concept of teaching triangle