# How do I write 'first and second order' properly?

I am writing about first-order and second-order quantities. Should I put one hyphen, as in

"first and second-order",

or two, as in

"first- and second-order".

Or should I do something else?

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Both your attempts are fine (especially if you're going to use the descriptor in the attributive position - eg first- and second-order differential equations. But I'd count your hyphens again. – Edwin Ashworth Feb 17 '13 at 15:02
Fowler recommends first and second-order quantities. – Cerberus Feb 17 '13 at 15:31
I'd dodge the issue and write first-order and second-order quantities. – Barrie England Feb 17 '13 at 15:38
I would use first- and second-order quantities. (I don't agree with Fowler on this point.) See this question: english.stackexchange.com/q/79159/18655 – JLG Feb 17 '13 at 15:44
What JLG said ... but only in the case of compound adjectives. If first and second are modifying order alone, no hyphens are required. – Robusto Feb 17 '13 at 15:58

The Guardian and Observer Style Guide offers and explanation on when to use the hyphen and when not to. If I can simplify it here (I assume anyone can read it for themselves at the link), they say hyphens tend to add clutter to the text and they are unnecessary where the meaning would be clear either way.

(That being said, I have the habit of using them for compound adjectives like the ones you gave in your examples.)

They do give an example where (they say) hyphens should be used with short compound adjectives (e.g., "one-tonne"). It's not clear to me why, unless there is some possible ambiguity that can arise. The give an example of this sort of ambiguity in the following quoted headline:

Motorists told:

don't panic