I've always written it like "1900s", and always considered "20th century" to be confusing. Having to mentally do c-- or c++ is confusing and annoying. I deal w

I've always written it like "1900s", and always considered "20th century" to be confusing. Having to mentally do c-- or c++ is confusing and annoying. I deal with the "2000s-problem" by using "00s" to refer to the decade, which everyone seems to understand. Sometimes I also use "21st century"; I agree with the author that it's okay in that case, because no one is confused by it. For historical 00s I'd probably use "first decade of the 1700s" or something along those lines. But I'm not a historian and this hasn't really come up.