订购数量的英文：
lot size

参考例句：

Could you please tell us the quantity you require so that we may adjust our price accordingly.
请您说明你们大概要订购的数量，以便我们对价格作相应的调整。

We have changed the quantity of PO No. A. Please make the delivery according to the revised order.
我们已经修改了订单A的订购数量，请你们按照新的数量出货。

lot是什么意思：
n. 很多，多数；全部；一批；一块地；签；抽签
v. 划分；抽签

to decide By lot
抽签决定

It was settled by lot.
这事是以抽签决定的。

It was settled by lotting.
这事是以抽签决定的。

They are a sorry lot.
他们是一批糟糕的家伙。

But it is a lot less clear than a lot of other objects.
但是和其它很多物体比起来,长城要模糊得多。

size是什么意思：
n. 大小，多少；尺寸，规模
v. 按大小排列或分类
adj. 一定尺码的

Will you size these nails?
你把这些钉子按大小分开好吗？

Row size exceeds max cache buffer size
行的大小超过最大高速缓存缓冲区的大小

What's the size of the pan?
这秤盘的尺寸多大？

apparent screen image size
表观放映画面

Range the books by size.
把这些按大小分类排列。