5 digit house numbers are pretty common throughout California, partly because in general, house numbers will start a new group of 100 each block, making it a lo

5 digit house numbers are pretty common throughout California, partly because in general, house numbers will start a new group of 100 each block, making it a lot easier to identify in which part of town a given address falls. So a given block will have numbers 102XX, the next block will have 103XX, and so on, even though the 102XX block may only have numbers 10200-10241, for example. What’s even cooler is that, in L.A. at least, block numbers are assigned so as to “sync” with each other; the 9800 block of Sepulveda is due exactly west of the 9800 block of La Cienega. And, cooler still, the 9800 block of both streets (actually, pretty much any north-south street) will be between 98th and 99th streets. The address numbering system in L.A. is surprisingly effective and consistent for a town that is essentially a patchwork of dozens of independent cities, with a mountain running through the middle of it to boot.