@tali,
House numbers don't work the same way in most of the US as they do in Britain. In Britain (and in many places in the northeast of the US) they start at 1 and number until they run out of road.
In most of the rest of the US, it's more like a grid system, so your 24300 South Figueroa is 243 blocks south of the "dividing line", which in this case happens to be 1st St. in Los Angeles. I'm not sure there's ever been any research done into this, because houses are continually being built. Along US Highway 1 near its southern end in the Florida Keys, house numbers refer to the mileposts (it starts at 0 in Key West and increases as it heads toward the mainland). The highest house number I could reliably find was the Anchorage Resort in Key Largo, the closest inhabited key to the mainland, which is 107800 Overseas Highway, Key Largo, FL 33037. That means it's almost 108 miles from Key West.
Where I used to live in Iowa, there were no physical addresses until 1999 or so; you would tell people you lived three mile roads east of the county line, or give the sort of directions that seem stereotypical (turn left at the rusted-out old tractor, turn right at the red barn with the 7-Up ad on it, etc.). Then, as Iowa implemented statewide 9-1-1, there had to be addresses, and so they implemented a per-county grid system, usually starting at the southwest corner (most counties in Iowa are more or less rectangular) and increasing as you head north and east. This meant that my house, which used to be Rural Route 3 Box 30A, was now 3210 170th Street, a gravel road more than five miles from a tarmac/sealed road.
In northern Utah, they take it to an extreme, where addresses sound like Battleship coordinates: 1131 South 1400 East, for example, is 14 blocks east and 11-and-change blocks south of Temple Square in Salt Lake City. (It gets confusing, because most people would call that street "14th East".)
In most cases, each town sets its own centre axes, so that in the city of Orange, California it's at Chapman Ave. and Glassell Street; in the neighbouring city of Anaheim the centre point is at Centre St. and Anaheim Boulevard, which means that if you are driving east on Katella Avenue, you go from the 2600 block of East Katella Avenue (in Anaheim) to the 1800 block of West Katella Avenue (in Orange) in one block.
It makes a lot of sense when you get used to it, particularly where it's been standardised across large areas. Hope this helps.