Factoid was coined by Norman Mailer in his 1973 biography of Marilyn Monroe. Mailer described a factoid as "facts which have no existence before appearing in a magazine or newspaper", and created the word by combining the word fact and the ending -oid to mean "similar but not the same". The Washington Times described Mailer's new word as referring to "something that looks like a fact, could be a fact, but in fact is not a fact".
Boy, that's a real good question. Some people are really starting to like the Python package NumPy for that type of thing, but I personally just like to use the Bible. Now, I don't know if Python or the Bible are better for doing numerical simulations, but I think people should be allowed to teach their children to use both. If you want to know which one is better, maybe you should ask a theologian.