When you get dressed in the morning, does it matter in which order you put on your pants and your shirt? What about your socks and your shoes? Which articles of clothing cannot be put on first? What about last?
Answering these questions led to some amusing debates among the kids. There were some that insisted that underwear needs to be put on before a shirt, while others claimed that socks can be put on top of shoes. But I think that most kids agreed that if A must be put on before B then B cannot be first and A cannot be last.
Here is a list (made with the oldest group) of all the possible orders in which shirt, jacket, socks, and shoes can be put on.
The discussions about getting dressed naturally led into our main activity involving colorful rubber bands. Initially, each kid was given a picture of a hand with several rubber bands on the fingers. The kids had to reproduce the picture with actual rubber bands on their own hands. While doing this, we told them to think about which ones could go on first, last, etc. For the youngest kids this was already quite a bit of a challenge. In fact, it took some of them a moment to realize that the rubber bands on the bottom need to be put on before those on top.
The older kids were then asked to come up with their own rubber band configuration, draw it, and then list all the orders they could come up with in which the rubber bands can be put on.
Finally with the middle groups, we had all the kids come up to the board and draw a configuration where the rubber bands either could be put on in exactly one order or in any order. The kids did a great job!