When lined up to leave the room, with backs to the wall, pass a baseball bat or yardstick from the front to the back of the line by using their feet (without kicking). Two or three students carefully lift it up on the tops of their feet at the same time and pass it toward the back, down the line without it touching the floor.

Think of ways food can make noise.

Think of 10 ways to get rid of junk mail.

Discuss how water might be made to go uphill with buckets, through a pipleline, forced through a sprayer, even from a tornado or hurricane; anything's possible in a brainstorming exercise. Fill up a couple of minutes discussing how pumps might work with pistons and valves, or with rotating turbines or blades.

Give students examples of square roots, if they don't know the term already, then have them estimate the square root of some large numbers, like 540, 27,000 or 8,000,000.

Have students describe the first place they would take a foreign visitor and explain why that place is important to them.

What if buildings were made of flexible materials? What are some advantages and disadvantages? What would it be like to be in one? What affect would weather have?

Think of different symbols for clock faces.