This requires you to summarize yourself and count the points deducted in recent exams:

First, if you can't do it, it means that you should strengthen your practice and don't be arrogant. Sometimes it is easy to make mistakes when you look simple, and you can't use carelessness as an excuse, because the small details of the mistakes are the standard to measure your mastery;

Second, if it is really some calculation errors that can be avoided, then you must develop a good habit of answering questions and write clear and standardized answers from class, which is also an ability.