I came across this post about cloud jars on the Teach Preschool blog and even though it is easy and preschool level, I thought my girls would get a kick out of it too. I really think this can be fun for just about any age. Really, shaving cream? Of course it is going to be fun!
Then we filled our jars with water, topped with shaving cream to make a cloud and proceeded to add "moisture" or liquid watercolors to the clouds. When the clouds were filled with too much moisture, it began to "rain" watercolors into the water. They thought this was so fun! They each did two jars worth before we moved on to making messy shaving cream art.