Nevertheless, it is always important to nip any problem that could cause serious difficulties later on as soon as possible. You need to work with your son's classroom teacher on measures that will help him focus better in the classroom. The teacher might seat your son in the front of the class or have him sit in a study carrel wearing earphones to eliminate some of the classroom distractions when he is completing an assignment.
At home, you should engage your son in activities that require his close attention. Play games with him where staying focused is essential. When you read to him, stop frequently and ask him what is going to happen next to keep his attention on the story. Give him tasks from setting the table to making his bed, and praise or reward him for handling them in a timely manner. And do limit his TV viewing time, as it does not help children lengthen their attention spans.
Be sure to observe your son when he is doing schoolwork to see if you can figure out what distracts him. Plus, why don't you simply talk to your son and ask him why he is having trouble at school staying focused and what could be done to help him concentrate better on his schoolwork. He might just know the answer.