I picked this "Post of the Week" due to the frustration you may have felt after bringing a new computer home and then wondering why the actual hard-drive size does not appear to be as advertised.
hpgnoul came to the forum recently asking this about this. You can read the full thread here. He questioned why a drive advertised at 250gb, would only appear to be have less.
The answer came in the form of a math lesson taught by Mumbodog and Cyclops. The answer even included this amazing bit of computer information. "250000000000(bytes) / 1073741824(bytes per GB) = 232.8 GB"
So, if you ever have doubts about the value of our community, just ask a math question. You'll be amazed at the knowledge we have here.