角(jiǎo) - jiao (1/10 of a yuan, written/formal register) in Mandarin

角 (jiǎo) is a unit of Chinese currency, one tenth of 元 (yuán) and worth exactly the same as 毛 (máo). The two words name the same coin: 角 (jiǎo) is the formal, written form you find printed on price tags, receipts and bank statements, while 毛 (máo) is what people actually say out loud when they are haggling in a market.

That written-versus-spoken split is the whole story of 角 (jiǎo). A learner who has only ever heard prices spoken aloud, for example 三毛 (sān máo), "thirty cents", can be caught out the first time they see the figure written as 3角 (jiǎo) on a receipt, because it is the same money, just in its formal spelling.

As a measure word, 角 (jiǎo) sits directly after the number and before 钱 (qián, "money") is even needed: 五角 (wǔ jiǎo) is simply "fifty cents" or "five jiao", worth half of one yuan.