Should I use a suspended hyphen here? “A group of five-to-nine-year-olds did it,” or a “A group of five- to nine-year-olds did it”?

The title pretty much sums it up. Which of the following sentences is correct?

"A group of five-to-nine-year-olds did it."

"A group of five- to nine-year-olds did it."

Moreover, would it change anything if the numbers were bigger, meaning that I'd have to use them as numerals (following the Chicago Manual of Style, which states you should use numerals for numbers over a hundred)? For instance:

"A group of ninety-nine-to-101-year-olds did it."

"A group of ninety-nine- to 101-year-olds did it."

On a related note, would simply exchanging the "to" for an en-dash solve the problem? As in:

"A group of five–nine-year-olds did it" or "A group of ninety-nine—101-year-olds did it"? (Using an en-dash between the numbers and an hyphen between the numbers and the nouns and between the nouns themselves.)

• A group of children aged five to nine did it. A group of people aged 5 to 101 did it. – Tinfoil Hat Oct 6 '20 at 5:01
• @Tinfoil Hat Thanks for the comment! Well, yes, that is a way to write it, while avoiding the use of hyphens and dashes altogether. I'm curious, though: why did you write out five in the first sentence and leave it as a numeral in the second one? Is it to match with 101? – Rustpen Oct 6 '20 at 11:29
• Yes, per Chicago, these should match. If you had a whole book of things like this, then don't just match within the sentence, match within the whole book. – Tinfoil Hat Oct 6 '20 at 17:41
• @TinfoilHat Sorry to bother you again, but I'd like to clarify this point. Would this mean that in nontechnical writing, I must either write out numbers or leave them as numerals? Aas far as I'm aware, Chicago recommends writing out numbers one through one hundred and leaving as numerals numbers above a hundred, so I assumed I'd use both forms in a book according to how great the number is (whether it's lesser or greater than a hundred). – Rustpen Oct 6 '20 at 18:06
• Not exactly. Some of this is a judgement call beyond Chicago. If you refer to ages throughout your document, and some of them (like 101) must be numerals, then make all the ages numerals. If, in the same document, you have apples, and you don't have more than a hundred of them, then apple numbers can be spelled out throughout. – Tinfoil Hat Oct 6 '20 at 20:56