Parents volunteer to organize and run the day. I think it gives those parents an appreciation of just how much effort, energy, creativity and required flexibility and quick thinking goes into teaching.
We had 10 stations, each having to do with the number 100. At one station kids built a snack mix with 10 pieces each of 10 different ingredients. At another they graphed food items brought in for a food bank. And at another they participated in the 100's Day Olympics.
I got to run the store! Big bonus, I got to do it with my friend Erin that I simply do not get to see enough of.
So... Erin and I helped groups of kids to identify which coins were in their bags (all dimes), discussed the value of a dime, and then counted by 10's to see what our spending budget was at the store. Naturally, each kid's budget was 100 cents...or $1. They got to pick from bouncy balls, fancy paper clips, plastic rings, stickers, bookmarks, note pads, etc. Many came in under budget and got to pick more, several bought items for their siblings...and some went way over budget and had to narrow their purchases to the items they wanted most. Talk about a real world experience.