My daughter loves watching PBS Kids and will view episodes on the IPad repeatedly. One day, she was methodically watching Sid the Science Kid, green slime experiment video,over and over again. She had the hand movements that the children do at the very end down to, well, a science. :)
She was bored and I wanted to attempt to cook something without interruption. I quickly whipped up a batch per their instructions and let her have at it.
I ended up using some blue food coloring, but we still had fun.
Note to parents - test out the ratio of cornstarch to water for yourself. I ended up adding a lot of cornstarch because the mixture was too runny.
Cleanup - As you can see from the photos, it was a gooey mess. The mixture dried and it was just a matter of getting rid of the cornstarch mix - pretty harmless. Just watch out for the food coloring dye to make sure you don't get it on your clothing.