Rainbow Roses Get white of cream colored long stem roses. (Carnations work well too). Cut the stem according to the picture, you will then place 4 glasses of food color dyed water together. Put one piece of stem per color and allow the flower to soak up different colors.
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.