According to the students' own preferences. I think taking some math notes is helpful for memory. Because many conceptual things were clear at that time, but they came back badly after a while. Secondly, for the answers to some technical exercises, students felt that they understood them at that time, and there was no problem, but they soon forgot them later. If it can be recorded, it will not be simply remembered by the brain. If you forget, you can also review by self-study. Improve the learning effect. Teachers can guide, but they don't have to force.