课堂练习是教学过程的重要组成部分，优化课堂教学必须优化课堂练习。要设计好练习，必须遵循以下原则1．目的性原则。练习必须要有明确的目的，不能笼统，更不能含糊。例如数学三角形面积，在推导出三角形面积计算公式后，传统的方法是出示类似右框中习题组：这样的练习，要求 Classroom practice is an important part of the teaching process. To optimize classroom teaching, we must optimize classroom practice. To design a good practice, we must follow the following principles 1. The principle of purpose. Practice must have a clear purpose, not general, but not vague. For example, the area of ​​math triangles, the traditional method is to produce a group of exercises similar to the right box after deriving the formula for calculating the area of ​​the triangle: Such an exercise requires