Scientific modeling is a scientific process that plays an integral role in students’ developing and communicating scientific understanding of observed phenomena. Scientific models indeed can be very useful in teaching abstract concepts. However, deeper understanding occurs when students are actually creating and using their own models to explain observations that they see in nature. Scientific modeling is rarely used in elementary school, especially in lower elementary grades. Scientific modeling is considered by many to be an abstract skill that is not developmentally appropriate for younger elementary students; however, scientific modeling like all other aspects of scientific inquiry has to be developed. The following is a pilot study to determine if a group of first graders at can begin to develop scientific modeling processes during a unit on the states of matter. The learning progression of modeling with these students will be illustrated to show that with careful guidance young children can effectively create, test, evaluate, revise and use models to explain observations of their natural world. By using scientific modeling, these first graders have clearly shown a deeper understanding of the states of matter.