Yeah, basically the way I remember it is that Great Britain is a geographical term rather than a political one, cus technically it also doesn't include things like the Isle of White, Anglesey off the top of Wales, the Hebrides, and...so on. Which is easyish to remember given the full title of the country separates the two geographic places, so you probably got it right?

Just make your students watch this!

http://www.youtube.com/watch?v=rNu8XDBSn10

:p