This is really cool to me. But it makes sense. It just uses a unique numbering system. I suppose instead of adding a new tens or thousands placeholder to increa

This is really cool to me. But it makes sense. It just uses a unique numbering system. I suppose instead of adding a new tens or thousands placeholder to increase the number, you just add a new grid reference. Pretty cool really. edit: I guess it's basically a base-9 numbering method, yes?