It is estimated that your child is now in primary school or junior high school. As a high school student, I have also experienced the stage when teachers asked parents to write comments. Personally, I think: I can tell him that grades are not the basis for measuring a person's Excellence, but they can definitely be used as a reference factor. As students, our task is to study. I think there are differences between people, but these differences are not the decisive factors affecting grades, but people's efforts. Mathematics is a subject, some are born strong and some are born weak. This is recognized as the most intelligent subject (space, logical thinking), but it's no big deal if you are willing to ask more questions, write more and think more. Do a set of wrong questions or exercises, collect all kinds of questions that you can't do in the exam, and turn over a page or two when you have time. When you read all kinds of questions, will intelligence still affect you?
Therefore, comments should be based on encouragement, rather than blindly accusing him.
I remember what my mother often wrote: this exam is not ideal, English subjects need to be strengthened, learning is endless, and God rewards diligence.
Work hard, but you walked up a flight of stairs and broadened your horizons by 300 miles. I hope you can make continuous progress.
Such comments give children positive energy, but they won't make them feel embarrassed by exams and comments scolded by their parents. I like them anyway!