3-6 yrs. The It’s All in the Box! preschool STEM kit developed by Hatch is part of the Science, Technology, Engineering and Mathematics (STEM) series for preschool STEM learning. This preschool stem kit focuses on 2-D and 3-D shapes, weight, volume, and construction for ages 3 & Up. A scaffolded Teacher’s Activity Guide is provided with research-based lessons that are aligned with national standards.