You need to ask. He is basically asking for assurance that it is YOU wanting his number, no one else.
I feel he has been trying to let me know he likes me, so I asked my friend to get his number for me. When my friend asked for his number he said, "tell her she has to ask me herself". What do I do?
Don't ask. You might look desperate if you ask him. Let him ask your number. The guy should put the initiative. Or else he may think that you are head over heels about him and take advantage of that. And don't assume. :)-- let him say first that he likes you. Cause maybe the slightest percent you just misinterpreted his actions.