It's a historical thing. I might even say it's a "bad habit" that Catholicism has. Some "habits" die hard. It's like the difference between a kilobyte and a kibibyte. A kilobyte used to be 1,024 bytes. Now they've changed it to 1,000 bytes because it confuses people. The kibibyte has replaced the kilobyte as 1,024 bytes. I don't like the change because I'm used to the old definition/tradition of 1,024 bytes. Shame on everyone who wants to change it to 1,000! You're probably wondering why they made it 1,024. It's because 2^10 = 1,024. The number 2 multiplied by itself 10 times is 1,024. That's pretty close to 1,000. The number 1,024 is a pretty neat number. 1024*1024 is still pretty close to 1 million, and 1024^3 is also still pretty close to 1 billion, and so on and so on. That's what makes the number 1,024 so special, much like a kind of mathematical elegance, in that the binary version of "kilo" is close to the decimal version of "kilo." 1,024 is a mythical, legendary number.