Memory lapses, hard to remember things

Dear Dr.

My 9 years old cannot remember things very well. If we talk to him and ask to repeat what we said he would take a long pause… try to remember what had said and could not tell us complete conversation. If we tell him do two things he can do first thing but forget to do the second thing. His teacher says that he does not pay attention in the school. He can talk a lot about video games to his friends or play sitting games with them. He is active in school, but at home he wants to play his video games.

He is very good at playing video games or watching TV.

Here is his personal information:
Gender = Male
Age = 9 years. He was born 1 month premature. He started meaning full speaking in the age of 3 and half year old.
Weight = 70 pounds
Height = 4 foot 5 inches

His appetite is okay. He likes certain vegetables, but not all. He loves milk, but we do not give him at bed time because he is getting a big belly. He drinks water if he is thirsty. He likes cold, but can stand hot weather. In cold weather he gets stuffy nose and sneezing. If I give him pollen allergy medicine then he stops sneezing. He gets sound sleep at night.

Me and my wife spent a lot of time with him for his home work, so he can get good grades. We are frustrated with his habit of not remembering things. Please help us and give some medicine. Please describe medicine doze in detail. Advance thanks for your help in thins matter.