The first project was to make "smoke" rings out of dry ice vapor.
If you want to replicate this, make sure that the hole in the cup is circular. On the first attempt we cut a rectangle and it didn't work very well.
The next project was a dry ice bomb. This project has a very real element of danger. Do you know my friend Gavon Barkdull? He had his wrist broken in two places when a dry ice bomb went off in his hand.
The last project was to make vapor-filled bubbles. Kenna was an expert at making the bubbles very large.
These are all easy projects, although adult supervision is mandatory. We only used about a dollar worth of dry ice. The other materials are all household items. Pretty cool, huh?