It's very hard to pull off a successful teaching demo in an interview. Reasons being:
- The interviews want you to give a demo, however it's not a "true" classroom environment.
- Time restrictions - Teaching what you normally would do in an hour over the space of 10 minutes.
- Many interviewers wont interact as would a student.
Well it's good that you know the age group to prepare for. With this age group, I would write in bullet point (4 points or so) of what will be covered over the following 1 hour lesson. Adults appreciate such outlines. Be sure to write this up for your demo lesson, so the panel can see what you would teach should you have the luxury of a full hour.
Before you start your teaching demo, explain to the panel that you will obviously shorten many aspects and interrupt students in order to move on.
This is something along the lines what I would do for a demo lesson:
- 2 minutes: General chit chat. Teacher asks questions about the weekend, current news events and encourages students to talk about them (either in pairs or open class discussion). Light chit chat and try to choose a topic of interest to students.
- 4 minutes: present a grammar structure. Eg: "The more the more". Write sample sentences on the board.
- The more I study English, the more I am understood when travelling abroad.
- The more I cook, the more I appreciate the flavours of food. (I know it's sounds better to say "The more I cook, the more I appreciate food", but it would possibly confuse students. So keep the sentences simple at this stage.)
- The faster I walk, the faster I can arrive to my destination. - 2 minutes: Ask students to stand and mingle with each other using the same structure just presented. During this time you would join up with the odd student or move around checking on students.
- 2 minutes: Ask students to write any sentence they want in their notebook. The rule however is it must use the above grammar structure. Then choose 1 student to write it on the board. Solicit from students if there are any errors in the sentence before correcting it. Idea is to get students to find errors instead of just having the teacher correct the sentences.
So that should be about it for a 10 minute lesson. If you don't have the time, you can always skip the last part. Be sure you also have a clock or watch so that you can keep track of time.
Good luck!