He gave you his number but did not ask for yours What does this mean?

It means that he might be interested in you, but he wants to be the only one to decide if he sees you again. If he flat out refused to give you his number, he is likely someone that dates a lot of girls and is just interested in sex. If he just didn't offer his number, just wait for him to call.. If he does, he does... if he doesn't, no big loss.