The key to engaging children in doing real science is to understand the difference between a "science demonstration" and a "hands-on science experiment." Demonstrations performed by the teacher typically illustrate a science concept. But science experiments give children the opportunity to pose their own "What if . . . ?" questions, which inevitably lead to controlling a variable--changing one aspect of the procedure or the materials used to perform an experiment. Children want and need opportunities to ask questions, make changes, create hypotheses, and compare the results of a new experiment with those of the first demonstration. Demonstrations may be one-time events, but experiments lead to questions, which lead to making changes and trying the experiment again. It's a wonderful cycle of critical thinking called "scientific inquiry." Effective science teachers use captivating science demonstrations to grab the children's attention and stimulate their natural curiosity. This article discusses how to get children excited about doing real science.