Yao (pin yin first tone) is a common way to say "one" in northern china when reciting multiple digits and basically the only way Beijing locals say 1 in a phone

Yao (pin yin first tone) is a common way to say "one" in northern china when reciting multiple digits and basically the only way Beijing locals say 1 in a phone number or a string of numbers. for going to a market and asking for 1 of something, "yi" is the preferred way. Pretty uncommon among southern Chinese people and Taiwanese (many American mandarin speakers are of Taiwanese descent).