3-6 yrs. Preschool STEM Kit - Gravity - If it goes UP, will it come DOWN? Introducing the concept of gravity in preschool lays the foundation for more in depth study later in school. Our 36-page activity guide includes a standards correlation and detailed instructions to guide the use of the materials. Prepare your children to blow bubbles, fold paper airplanes, roll marbles, and much more! Children will predict, test, and observe to develop evidence-based conclusions and practice using the scientific method.