I am holding one end of this paper strip so the rest sticks out. What do you think will happen?

Hands up with your guess: will it stay out, or will it flop?

Can a fold stop a strip of paper from flopping?

We will try it with our hands and find out.

We will try three ways, one at a time. Use a fresh paper strip for each try.

1. Hold a flat strip from one end. Feel what happens.

2. Fold a new strip into a deep V. Hold one end again.

3. Fold another new strip into zigzag folds, like a paper fan. Hold one end.

Each time, hold one end only. Do not put anything on top. Feel what your hand notices.

Tell your partner what your hand felt on each try: the flat strip, the deep V, and the zigzag fan.

Which one felt strongest? We will hear a few ideas.

Some shapes have a ridge: a raised wavy line, like the wavy middle of a cardboard box.

With the group your teacher gives you, look around our classroom for folded or ridged shapes that are holding something up. Find at least one example.

On your Investigation Journal page, draw one you found. Show where the fold or ridge is and what it is holding.