Here's a quick regional diversity quiz. Tell me how you say 1/4, and where you are from. A quater, from Australua..

Generally, one quarter. Canadian here.

”one fourth" as a standalone abstract concept and "a quarter" or "one quarter" if immediately followed by imperial units of measurement (i.e. "a quarter cup or flour"), although I'll say "fourth" in baking etc as well

a fourth then when someone says what because I mumbled, I will say ONE QUARTER Minnesota USA

Either “one fourth” or “one quarter”