Is there a difference between a written-out fraction that serves as a noun:
He gave me one half of his sandwich.
and a written-out fraction serving as an adjective:
I gave her a one-half share of my cookie.
I say a fraction serving as a modifier should be hyphenated as a phrasal adjective. A fraction serving as a noun should not. But everyone I work with hyphenates fractions no matter what their part of speech.