I can help you. My son now invites Mr. Guo from a key middle school. The "Guo Mathematics" he founded just corresponds to my son's weakness. It's only been a month now, and my son's grades have improved by nearly 20 points. The point is that he has become confident. He clamors for me to buy him an extra teaching aid book every day. He likes to do math problems. Unfortunately, it seems that Mr. Guo's phone number can't be published here, otherwise it won't be published. Search "Guo's Mathematics" by yourself.