Demo Lesson question-math

So I've been on child care leave for a couple of years and I'm looking to go back to the city, but a different school. I have an interview Monday. They are having me come in for the interview and do the demo lesson all in one day.

They said I could pick any subject. It's for a Special Education position. I'm also certified in math and have taught that, so I'm going with math. It's either 6th or 7th grade. They said I can pick the subject and topic.

It's a 20 minute guided instruction lesson. These were my ideas for a topic. Any suggestions/input? i've actually never done a demo before! I feel like 20 minutes is SOO short!

My ideas are as followed:

-surface area of a rectangular prism
-circumference of a circle
-adding integers
-something with fractions maybe adding or multiplying
-solving 2 step equations
-solving proportions

Thoughts on these topics? I'm trying to think of something I can do that is hands-on and something that can be done well in 20 minutes. Suggestions or tips are welcomed! Thanks!!

Re: Demo Lesson question-math

I would do a hands on surface area lesson. I would have the students dissect a prism (cereal, tissue box, etc) and have them figure out the area of each piece and show how that relates to the surface area formula.

Re: Demo Lesson question-math

That's how I normally teacher surface area, but do you think that 20 mins is enough? The time makes me nervous

Re: Demo Lesson question-math

I think if you do it as a guided investigation 20 minutes should be good.

Are they looking for the complete lesson? Open/mini lesson/close/ec?

Re: Demo Lesson question-math

By the way, if you are looking for a high school position send me an FM. We are still looking for a special ed and/or math teacher.

Re: Demo Lesson question-math

They were very vague with what they are looking for. They just said 20 minutes guided lesson for 7th grade. I would teach hs. I'm looking to stay in Queens. Where is your school? I'll FM you now. Thanks!