I saw and liked your video on how many rectangular shapes in 8*8 grid. How about this expanded to 3d ? this seems much less commonly discussed, and more interesting. Any chance you do a video about that ? I was thinking you expand the 3.3 to 3.3.3 with 4C2 * 4C2 * 4C2 which is 6.6.6 which is 216. But when I try to visualize it, I think I see more possibilities, but am not sure if I am duplicating ... I think this would be a great video. ps, I love your videos, keep up the great work.