This DIY teacher kit consists of what might be readily obtainable supplies for many, yet hard to find, let alone procure, in some locales. However, even if you the teacher are in the latter category, with no budget or access to a big inventory, it's all about mapping out conceptual content, meaning you'll be able to follow in your imagination, just based on what's depicted.
What's depicted is a pyramid of clay balls, approximately the same size. There's an imperfect handmade feel to the balls and in some claymations I'd substitute more perfectly formed clay spheres. Behind this pyramid are a couple envelopes with balls apparently drying on them. The clay balls must have been painted by what's in those squeeze bottles. We see Red, Blue, Orange, Green, Yellow, and uncolored balls.
Earlier, I'd colored the balls using Sharpie pens, by poking them with colored dots all around, accounting for their roughness now, as what I did is paint over them (except for Yellow, too far gone, started over with that one).
The goal, using more clay I'm harvesting from around the facility (I hope to not open the sealed clay brick depicted), is to add one more layer of balls to any face and then swap out the corners with their colored counterparts, in a particular ordering orientation we call BRYG.
By adding a layer, taking the displayed 3-frequency 4-eyes (colloquialism) to 4-frequency, I'm creating what we might call a first nuclear ball, equidistant from the four corner balls. By convention, I tend to color that one Orange.
I'll then calibrate the tetrahedron as a whole such that my edges are one diameter (subdivided into four or whatever frequency), and therefore my spokes, from the Orange ball center to any corner color ball center is 2nd root of 6, over 4 i.e. $$ \dfrac {\sqrt {6}} {4}$$
