How to pronounce quarter

I think the reason why Americans say fourth more in the math context, is that people in general don’t like homophony. In American English, quarter most commonly refers to twenty five cents: In the US and Canada, unlike in the UK, New Zealand, Australia, there is a common coin worth 25 cents called a quarter.

For example, the Oxford English dictionary entry for “dwarf” gives the British pronunciation as /dwɔːf/, and the U.S. pronunciation as /d(w)ɔrf/.