What's in a number?

In Europe, numbers usually run sequentially from one end of a street to the other, generally odd numbers on one side and even on the other. Street names will often end at a junction and a new street name will start the other side with a new set of numbers starting at 1 or 2. In the US however, numbering is based on a lot and block system (devised in the late 1800s) which is simply a way to divide up large urban subdivisions into manageable chunks.

These ‘chunks' are called blocks and they could be numbered anything from just a few up into the high hundreds depending on the size of the original subdivision and the size of the blocks. So for example, a 100 acre square subdivision called Johnstown (wishful thinking!) might be divided into 200 blocks. The blocks don’t have to all be the same size and they aren't necessarily square, depending on topography etc. These blocks are numbered from 1-200. The block will then be divided, let's say into 20 smaller lots, again, not always but often of similar size. So, in block 125 for example, those 20 lots within it will be numbered from 12501 to 12520. Above is an example of another block with 14 lots divided into it so they’d be numbered from 7001 to 7014. 

The really confusing thing is that if you travelled along the north side, coming in from the west, the numbers on the block would start at 7 and go up in sequence. But if you came along the south side of the block the numbers start at 5 and go down to 1 and after 1 it goes to 14. Thanks heavens for GPS!