You may or may not know that the verb atone comes from the phrase at one (it originally meant ‘to be reconciled’); now that you do (if you didn’t before), it may strike you as strange that the “one” part is pronounced so differently from the number. Well, that’s the “correct” pronunciation; the one for the number has undergone a dialectal shift that also produced /wət/ for oat, although the latter has stayed dialectal. And the OED says: “The orthoepist C. Cooper (Grammatica (1685)) draws attention to the latter development when he describes the pronunciations wun for ‘one’ and wuts for ‘oats’ as ‘barbarous speaking.’” So there you have it: those who dutifully obey the dicta of modern orthoepists of the Safire variety should immediately cease using the barbarous pronunciation that has so unfortunately overtaken the word one. What matter if no one understands you? A small price to pay for knowing your usage is unimpeachable!