I actually had just experienced creating my own "STEM in the Box" in my Science foundations course for my college program. Basically, "STEM in the Box" is a term that is basically self-explanatory. It's literally just a science activity in a box! The idea is to get students engaged in a lesson through an activity that aligns with an NGSS standard. In this case, I would create a STEM in the box activity for Earth and Science for elementary students! I would start off with looking for a specific standard that you would want to teach. Here's an example:
4-ESS2-2 Earth's Systems
[color=#333333][size=2][font="Helvetica Neue", Helvetica, Arial, sans-serif]Analyze and interpret data from maps to describe patterns of Earth’s features.
With this standard, I can create a box that contains different maps of the world. These different maps could have different features of the Earth such as different surface like Terrains, deserts, mountains, oceans, etc. Some physical objects, I would include would be things that the students could "feel" to get a sense of what these features look or feel like. I would also include some worksheets for students to collect data of their findings.
STEM in the Box is a simple yet engaging way to make a science lesson! Hope that helps! :)[/font][/size][/color]