Here are few examples of hyphen usage I found (albeit on internet) for numbers with preposition in between. At the same time I find these without hyphens in similar usage.
So my question is, are their any rules of hyphen usage for numbers that are glued together with a preposition? If there is a rule, then a reference to the rule will be greatly appreciated.
The only rule that seems to exist is ... when it is used to describe a noun and the description is before the noun with the unit involved always in singular form (e.g. inch) like so.
- "Line the bottom and sides of a 13-by-9-inch cake pan with foil, ..." LATimes
I believe #-by-#-unit case falls under Rule 4 of The Blue Book of Grammar and Punctuation: Hyphens but I wonder if anyone will raise an eyebrow if the above example was written without hyphens like: "Line the bottom and sides of a 13 by 9 inch cake pan with foil.