What comes after Ninety Nine?

The article "A" usually precedes the word hundred when we say it. So technically it's right because "A" means a singular noun. There are words that you don't have to completely say because it has been used colloquially.

It highly depends on context I believe. If we're counting I would use "one hundred". However when we talking about amounts (like money) we usually say "I need a hundred USD/EUR/GBP", "five hundred toys". He has a hundred folders. However either option is valid in the English language. Cheers! Pablo

It depends a great deal on the context. If you are counting, it is generally " ... 99 ... one hundred ...", otherwise it's usually "a hundred" unless you need to emphasise the "one", so "a hundred dollars" or "only one hundred dollars!" If there's a number in front, it's just 'hundred' (five hundred, &c), otherwise it's 'a hundred', 'many hundred' but 'many hundreds of'

I say uh hundred, or a hundred. I've said one hundred, or just hundred before, but uh most of the time comes before hundred.

im not sure.. i guess i never really thought about it.. i would think one hundred but hundred or a hundred might equal the same thing

I almost always say one hundred. It sounds more proper. A hundred sounds hickish to me, and as I live in a southern state I try to avoid any of the southern accent traits we have. It seems to work. One hundred is also more precise, rather than saying "A hundred or two" which just seems like a person has no clue how many things he or she needs.