I have this problem regularly with younger students at the trade school level: I am discussing a subject, focusing for the moment on a particular part of the classroom, when there is a discussion between two students in another area. When I indicate that they are talking while I am talking, they say "but we are talking about the subject too!" (Not always likely of course.) How might I address this? When I say they should just bring it up as a topic of discussion, they just look disgusted and annoyed with me. I have yet to come up with a successful solution to this.