There is a principle in education called teaching students in accordance with their aptitude. I think you know very well that it should be very difficult for such a child to complete the tasks given by his parents in a short time according to what you said. Of course, you can also try to help him learn math from the perspective of low IQ. For example, let him experience this action and personally measure the side lengths of squares and rectangles. In fact, the concept here involves the inclusion relationship between sets, and children may be very insensitive to abstract things and nouns. In addition, if he has problems with addition and subtraction, it means that his foundation is basically poor. You can directly feedback this situation to your parents, and then provide you with a review plan and general goals. I hope parents can cooperate with you. If parents don't care about anything but asking for review, you can clearly say that it is almost impossible.