Correct usage of (n)fold, where n is any integer greater than or equal to one? [closed]

Question

Writing a rhetorical piece for my high school english class, I wanted to emphasize the sheer increase from 10 million to approximately 2 billion.

Conveniently, 10 million is 200 times smaller than 2 billion. That makes a nice, clean number to work with, even though it really doesn't have any significance on the quesiton I'm asking here.

What I wanted to do is to say something like this:

two hundredfold

or

two hundred-fold

Just as

twofold

means two times as many. The pattern appears to be placing the number before fold like threefold, fourfold, fivefold, etc.

Yet, with something like two hundred, how should I space, hyphenate and spell it correctly?

Just wondering because I'm a little ocd about this and would like to get it right.

Answer 1

@Mike's answer is simply wrong. Firstly because hundredfold is not a noun, it's an adjective/adverb, and secondly because the correct form for two of them is two hundredfold, for which there are over 1700 written instances in that link (and not a single one for the pluralised version).

Note that in principle the -fold suffix can be attached to any number term, and it's irrelevant if that term includes spaces, as in two hundred. I don't think anyone would ever write one hundred and forty-fourfold, but it would be valid.

But it's worth noting that hundredsfold is valid, because although it's imprecise, hundreds is a valid number term.

Answer 2

"Two hundredfolds" is not correct, and "hundredfold" is not a noun. From NOAD:

-fold |fəʊld|
suffix
forming adjectives and adverbs from cardinal numbers:
1 in an amount multiplied by: threefold.
2 consisting of so many parts or facets: twofold.

For example, in the film The Big Lebowski, the big Lebowski tells The Dude:

And with Brandt as my witness, tell you this: Any further harm visited upon Bunny, shall be visited tenfold upon your head.

So words using "hundredfold" follow the same pattern.