Number one ? The First?

香港人又會講the first..
又講number one..

我係英國嫁..
唔會有人講number one去表達第一.
人人都係講the first
因為number one既中文係"一號"

我認為number one係一d唔係好識英國既人講...
因為佢地可以聽人講..
所以跟住講
其實the first先係第一既讀法
希望我地呢個年代既人開始更正返呢個字

In U.S. number one is used a lot. "X is the #1 tourist destination." "He is our #1 sales rep." As the other answer said, first - earliest time wise, #1- top in sales, size, etc. The first car dealer and the #1car dealer means totally different things.

It should be ' the first'
'Number one' is a bit Chinglish

First, second, third.... usually written when it is about 第幾 or 第幾層
e.g.
I have got the THIRD in the class.
My apartment is on the FIFTH floor.

One, two, three .... usually written when it is about 數目
e.g.
I have TWO pencils.
There are THREE girls and TEN boys.

one, two, three, four, five, ... (數字)
first, second, third, fourth, fifth, ... (序數)

第一是用(the first)才是正確.

例句:
His horse was the first in the race.
他的馬比賽中得第一.

而 number 加數字,則多用於街號上.

First refers to the time order but not position. When we refer someone is No. 1, it means he or she is the top in terms of postion. Ie He is the top student. He is number 1.
You will not say he is the first student. He is always the first student to arrive at school. That is time sequence

So, when we refer someone as number 1 it is in order of ranking not order of time.