Note that unlike in the usual textbook approach, we start with factoring, then go on to the distributive law. This makes sense, because in this environment, students readily understand "make a rectangle", and that lays the groundwork for an explanation of the distributive law that they can actually hear. Because it is so important and foundational, there are lots of puzzles, worksheets, and lessons about this in the books — going a lot further than the examples given in the video. Possibly useful in discussing all this (after working with the blocks): Multiplying Binomials "Make a Box", and all 3D activities are especially popular with students. Most 3D work is in the Algebra 1 book.