Being those ages, I would say they are old enough. My oldest is almost 9 and my youngest is 2, so finding chores for all the kids to do sometimes gets creative and helping is sometimes just a drop in the bucket, but they are learning that they need to help around the house. If your son likes to help in this way and he does a good job, I would think it would be fine! Some people think kids should only sit around and play video games all day long and have everything handed to them and not have to work for anything! The more skills a person has, the better prepared they will be for life in the real world.