井号的英文：
well number

number是什么意思：
n. 数；号码；算数
v. 给…编号；计算，数

The number was fifty.
该数字为五十。

There is safety in numbers
人多势众

It was an irrational number.
这是一个无理数。

Which number on the card is a prime number?
在卡片上哪一个数字是最初的数字？

The number raised to the logarithm of a designated number in order to produce that designated number.
被升到指定数字的对数上的数量,是为了得到那被指定的数目。