Hyphenating spelled-out fractions with large numerators and/or denominators

Question

I find myself in the awkward position of needing to systematically spell out fractions where the numerator, the denominator, or both have three or more digits, and I'm not sure about the hyphenation. For example, 124/145:

• one-hundred-twenty-four one-hundred-forty-fifths?
• one hundred twenty-four one hundred forty-fifths?
• something else?

Answer 1

Can you use numbers at all? Could you write 124-145ths? Otherwise, I hate to say it, but stylistically, you should have a hyphen between the numerator and the denominator (rule 3 in the link). Also, it looks like you should use hyphens only with twenty-one to ninety-nine (Rule 7). So

One hundred twenty-four-one hundred forty-fifths

would presumably be the appropriate style, according to the Blue Book of Grammar and Punctuation anyway.

Because you are using large numbers, maybe you could get away with an en dash instead of a hyphen, for clarity:

One hundred twenty-four–one hundred forty-fifths

Answer 2

The first thing I would look for is a style guide relevant to your awkward position that needs these to be written out. If something or someone is asking you to do this, go to them for the correct behavior.

Aside from that (or convincing them this is a bad idea), I would use a word to split the denominator and numerator (depending on context):

one hundred twenty-four over one hundred forty-five

one hundred twenty-four divided by one hundred forty-five

The other complication in this is how to write compound fractions such as 1 3/4. I use and to split them:

one and three-fourths

six hundred and one hundred twenty-four over one hundred forty-five

This is still annoying and slightly ambiguous, but that is what you get when writing out numbers like these.

Answer 3

I think there is only one way of hyphenating this and making it moderately clear: put hyphens between all words in both the numerator and denominator, and a space between them:

one-hundred-twenty-four one-hundred-forty-fifths.

I know this isn't what the style guides say, but the style guides also tell you not to write out numbers this complicated; they weren't designed for this situation.