幺
yāo
youngest
surname Yao; most junior; tiny; one (unambiguous spoken form when spelling out numbers, esp. on telephone or in military); one or ace on dice or dominoes; variant of 吆[yao1], to shout
他报出的电话号码里有两个幺。
tā bào chū de diànhuà hàomǎ lǐ yǒu liǎng gè yāo。
the phone number he read out had two ones in it.
军人说号码时常用幺代替一，避免听错。
jūnrén shuō hàomǎ shí cháng yòng yāo dàitì yī，bìmiǎn tīng cuò。
soldiers often use yao instead of yi when reading out numbers, to avoid mishearing.