There are five ways:
zêg8 - zêg8-gai5 一個 - one
First: doin6ig8mian5 第一名
Where do you live? I live in flat one: ig8mung5 一門 = flat one
Now when giving telephone numbers we say one as iao1 么
119 - iao1 iao1 gao2
Now when buying things: one dollar or one Yuan we say as gai5-ngeng5 個銀
one hundred dollars or one hundred Yuan as bêh4-ngeng5 百銀
and finally: the first building or first block we say tao5goin1 頭間 which represent 第一間 in Chinese
You can watch the above explained in this video
Just one note: he said 最難學的字 as zuê oh4 oh8 gai dzi:
We should normally say siang6 oh4 oh8 gai5 dzi6 上厄學個字 - and not zuê as the presenter said: that is if you want to really speak our DioSua Uê accurately
zuê 最 is a Mandarin word. If you do not believe me, then look up your Diosua Uê dictionary and you will find this to be true.