What we did:
We put plates of milk out and added four different food colors to the milk. Then we had the students draw their observations on small disks that looked like the plate of milk. Then we went back to our plates and added a q-tip of dish detergent to each bowl and suddenly the bowls were mixing and moving colors all around the plate. Our rainbow milk was changing before our eyes. Students then went back and drew another picture about what the plate looked like when we added the dish soap.
We are looking forward to this once a month shared science experience with our 1st grade friends. The students did an amazing job, sharing materials, helping each other out, and most of all being great scientific thinkers.