Friday was a study on randomness and parental authority.
First off, I had the kids guess where a balloon would land once I let go of it. (More often than not, it landed behind me while the kids were in front of me.)
Once that was done, we ran balloon-on-a-string races. The background theory was: kids (balloons) run wild without parental guidance (string).
And for the younger kids, a bonus --
this. Natalie dubbed it a "torcano" (tornado + volcano, I'm guessing).