I have an interview coming up after half term that has been arranged by one of the teaching agencies I'm part of. It's my first interview since I've graduated and I'm trying to think of ideas for what I could possibly teach, however, I'm at a bit of a loss as to what to do. I have been told that I can either teach a 20 minute literacy or numeracy lesson, it's up to me to decide which subject and also to decide upon which topic. I believe it's the freedom in choice that's made my brain go blank. I'm very used to just being given a topic and then going off and brainstorming ideas for what I could possibly do. Can anyone give me any advice on how to decide upon a topic for an observation if one hasn't been specified? Particularly, deciding upon a topic for a class you don't know and a year group you've never taught? I really feel that as soon as I can decide upon a suitable topic, my brain will kick into gear and start generating some ideas so any help with this matter would be appreciated.