"Julia has eighty-two pairs of pants."
Translation:Julia hat zweiundachtzig Hosen.
I disagree -- drei Paar Hosen would imply that there are six pairs of trousers: perhaps two blue pairs, two yellow pairs, and two green pairs, so that there are always two pairs of trousers that belong together and form a pair.
German doesn't use Paar for trousers the way English does; it doesn't consider a pair to be the two trouser legs together.
Actually it pretty much is required, at least in US, Canadian, and British English. I have on occasion seen numbers like eighty-two spelled with a space instead of the hyphen in very old (e.g., 1800s and earlier) texts, and I suspect that I may have once or twice seen such numbers written as single words, but those are genuinely exceptional cases in the modern English with which I am familiar.