Demo lesson in 3rd grade

Help! I went on an interview on Tuesday and they called me yesterday to say they want me to come in for a demo! All i know is that it is 3rd grade and im stuck! I have no idea what i should do it on! Any suggestions????

I'm a 3rd grade teacher & the primary aspects are multiplication & the start of division; also writing a strong paragraph and in science we just finished a unit on volcanos.

You may get some ideas on www.teachers.net

Can the lesson be in any subject? How long do you have?

Cindy

The demo is Tuesday! I wanted to keep it fairly simple because i really dont know what their prior knowledge is.
I was thinking of reading the book Hairy, Scary, Ordinary and breaking them into groups and giving them an object (such as different food items- lemon, dry macarroni, bread, etc.) which they will have to use adjectives and their five senses to describe and then for closure having them give the adjectives to the class and the class trying to quess what they might be talking about (inferencing)

i was confused by the title of this post....i thought a kid gave a demonstration on something....