My unker² still using traditional word, call it 五錢. Sound like ng5 cin4. According to older generation, when they were "shipped" here during the cultural revelation, they have no idea how to value Malayan currency. Hence, they straight named the 50cents coin as a WEIGHT instead of actual currency phase value. For example:

在武曌亲自监工之下，就在耀州工坊铸造的五钱重的银币

However though, back than Canto fellas are the more lansi fellas, most profession now known as RUNNER, those eat brain fellas that work less, no proper job, but get to earn a decent living due to PANAI(pandai in Malay) CHAT HAI and got skill to deal with the Brits. Most Canto fellas are happily earning their own race money in Ipoh and never leave the town. The Hakkah fellas are usually the tauke of milling work, business owner, Cainis tabib that open medicine shop, tin miner that makes good moolah, but when go to town had to search for a Canto fella, give the canto fella 50cents to help bank in lar, pay bills lar, do all the admin work. So the Hakkah fella will usually say something like:

五 錢 比 開 你 還 唔 幫 我 同 而 只 死 紅 毛 鬼 喊 佢 去 食 屎
Hmm Chian Bin Hoi Ngee Han Hmm Bong Ngai Tong Eh Zhak Si Fung Mao Gui Gong Ham Gee Hee Sit See
Translate: 50cents ady given to you, still not helping me to ask the redhead(calling the Brits back then) go eat crap

From there, the Canto fellas in Ipoh started to adapt their Hakkah boss calling it as CHIAN instead of CIN. Originally, the Hainanese fellas also very pure, but there's just too many Hakkah & Canto fellas going to their shop to drink kopi and eat, so the Hainan fellas also call it CIAN ady

Another interesting fact if you keen to know. Have you ever wonder why they call it 五錢, but when ask how much that time will use 幾多looi? Because the LOOI came from our local Malay call it DUIT, and where DUIT came from? DUTCH Supposed to be BERAPA WANG! Not BERAPA DUIT! DUIT is a foreign language. The Belanda bring in their own DUIT(refer WIKI please). And surprisingly, when I check with my Hongkee fren, our Canto dictionary indeed got 鐳 leoi4 recorded as(money/currency). Then only realize, yes HongKong was once filled with Orang Belanda as well, so as Indonesia.

As for 5 bucks, in Ipoh still widely calling 5蚊. Whereas most of other places calling 5 kaw, thanks to the Hokkien influence. 五塊GOH KOH. Then the other fellas try to use it but broken jor, ended up HMM KAW ady

Interesting eh