化学计算是中学化学的重要内容．教学中，如果能着力精选习题，重视题型的变化，寻求解题规律，就能使学生跳出题海，提高解题能力．1转换思维，一题多变很多试题源于教本却高于教本，因此，教师一方面要注意基础，守纲条本，抓住知识点，另一方面，还要加强对知识考查方式的研 Chemical calculation is an important part of middle school chemistry. In teaching, if you can focus on the selection of exercises, emphasis on changes in the type of questions, seek the law of problem solving, you can make students jump out of the sea and improve the ability to solve problems. A change of thinking, a change of questions Many test questions originate from the textbook but it is higher than the textbook. Therefore, teachers should pay attention to the basics, observe the guidelines, and grasp the knowledge points. On the other hand, they must strengthen the study of the way of knowledge examination.