My daughter is entering a science fair competition in 3 weeks. I'm helping her with her experiment. She is 10 years old, in 4'th grade and about average to slightly less interested in science. I'm trying to come up with an idea that meets the following criteria... I want it to be at a level where she can do it, maybe with a little help. Not so difficult that I wind up doing it while she watches. It needs to be something that a 10 year old girl will find interesting and fun. I want her to have fun memories associated with science so that she learns to like it. It needs to address a real question with an experiment to find an answer. A demonstration is not an experiment. Any ideas?