Everyone remembers their very first slip and slide out in the yard on a hot summer day. Here's a variation.
Get approximately 50 feet of plastic tarp and items that would be found on a banana split (ice cream, strawberry syrup, caramel syrup, chocolate syrup, banana pieces, and maraschino cherries). Pile items on top of the tarp and spread them out. Add a little cooking oil for extra slip and slide. Have students line up and take off one at a time!
We've done this with just Hershey Syrup (about 50 lbs. found in bulk at Sam's Warehouse). Had we not mixed a little oil and water with it, we wouldn't have been able to slide very well.