Took me a while too. I wonder how the postmen operate in such areas... Or maybe there's another number at the fence of the property! Probably. Otherwise I don't think this should be allowed. Hey! It has the same format as the 'spelled out' thing, but we haven't seen square root yet, right? It's cool that it's an integer.
I personally expect the number to be near the door, so I found it almost immediately. That is what I wonder too! Many of the American houses I find/see have a hard to find number, or no visible number at all! Seems a bit inconvenient to me.
