So my mom (Oma) bought Isabelle this really neat children's science kit for her birthday. The first project we ever did was simply mixing colored water in test tubes with a dropper. She was hooked ever since! She loooooves it! Sometimes Hannah comes along for the ride.
This particular day we colored celery stalks and made raisings temporarily float with bubbles from carbonation. Fun stuff. I love little parenting aids that are so simple to use.