Here’s some more tips for your teaching interview:

State at the very beginning what you want the session to achieve.
Don’t though, say that you hope the lesson gets you a job!
Be realistic: in your half hour slot, you’re not going to cover a whole topic – merely an aspect of it.
In a mixed group treat boys and girls equally at all times.
Be honest, don’t pretend to be the font of all knowledge about your subject.
Remember, the best teachers are the ones that don’t know everything!
If you make a mistake say so and say so clearly and definitively – respect in the classroom comes with honesty.
Always smile!
Aim to learn the names of at least six kids in the group and use them.
Three of each remember – 3 boys, 3 girls!
Get them to do something – at the beginning, in the middle and at the end.
Thank them for what they’re doing before you start, thank them for what they’ve done afterward.
Always leave time to sum up what you’ve done at the end.
Always relate and explain what you’ve actually done to what you set out to do.

Don’t panic – its probably gone a whole lot better than you thought it would.!