This is a really fun project idea I've had in my head for a while, and here's how to pull it off.
Step 1: lay out a tarp that covers the square footage of a typical grade school gym, weigh the tarp down at the corners, and drizzle large quantities of acrylic paint on the tarp, in varying colors, of course, and then arrange the scooterboards along all four sides of the tarp.
Step 2: dress down the kiddos either in homemade ponchos made from trashbags, or in clothes that you don't mind having paint splatters on, along with goggles for eye protection.
Step 3: unleash the kiddos and let them have fun rolling through the paint on the scooterboards. They're guaranteed to have a blast with this project, as they'd be letting off built-up energy in a really creative manner, while also making a huge mess. :D Finally once the project is done and overwith, put the class's masterpiece somewhere to dry, and then hang it either in the gym or the hallway for everyone to see.
PS: This would be really fun with glow in the dark paint as well, in addition, rollerblades would work really well for inviting the staff in on the project as well.