Bottle Ecosystem, This is the most awesome class idea to teach ecosystems! Its self contained and you can observe the activity for the rest of the year. No mess no fuss and all of this cost about 17 dollars.
Weather: Fill the cup with water. Put shaving cream on top for a cloud. Explain that when clouds get really heavy with water, it rains! Then put blue food coloring on top of the cloud, and watch it rain. Kids love experiments! WEATHER UNIT by jenniferET