Before that, you might as well test him with some practical problems in games and life, and insert math problems into his favorite games, and the learning quality will gradually improve.
Education can't be completed at once, so it's most important for you to be patient, let your children get in touch with real life as soon as possible and be open-minded. Some famous scientists among financial economists or celebrities who have made outstanding achievements in various fields are not particularly smart when they are young. So I suggest you don't worry too early. Let him learn manners, form good habits and develop a lively and cheerful personality, which is the most important thing. IQ does not necessarily affect his life, but habits and upbringing are the peak of everything.