@Joel
Everyone's pretty much covered that your IP ranges won't really have any effect for security or anything. But I guess to try to answer a little more of what you're asking, I'd say subnetting is really for situations where you'd walk in to set up a network given guidelines like "We need 20 subnets, with up to 600 addresses on each subnet", or "We need 5 subnets, with however many addresses on each".
Subnetting's pretty much just the math that lets you take those guidelines and make sure you'll have them covered. Like others mentioned, it's based on binary.
For example, it ends up on a basic level not really mattering whether you need 600 addresses or 700 per subnet, because everything is based on the pattern 1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024...
Once you need more than 512 addresses per subnet (actually 510 for other reasons), your subnetting results won't change up until the point where you'd need over 1024 (really 1022).
Solving to make sure you have the number of subnets you need is also based on using that same number pattern to split up the addresses you have to work with.
Other sites can explain binary counting a lot better than I could try to, but 8 bits of data can work together to represent values from 0 through 255 like we see in those network addresses (256 values total since we started at 0).
Any address like 10.2.208.144 doesn't tell us much by itself about what's going on around it, but if you know what the mask is from /8 to /31 or so, it'll be enough to figure out the usable range of how many other addresses might be in its network, what the subnet's broadcast address is, where the next subnet starts, and how many other subnets you have to work with.
I watched Jeremy Cioara's CBT Nuggets and thought he was great. He talked about how much trouble people can have with subnetting and its math, but to me he taught it really clearly. He joked being facetious once about starting to use 10.x.x.x ranges instead of 192 ranges because they're cooler and "more professional", but really there's not any hidden benefit before your guidelines require you to have more of a plan for your subnets, for reasons others have mentioned.
In the past, the range of addresses was split up into different ranges or classes, but they don't really come into play any more. About right after I learned about the classes, I learned they come up more on certification tests than in other environments.
