subtraction

The restaurant suffered a subtraction in the number of customers.

这家餐馆的顾客减少了。

The trees cut down are counted as income but no subtraction is made for using up the forests.

砍伐的树木被算作收入，但耗尽的森林资源却不计入损失。

She's ready to learn simple addition and subtraction.

她准备学习简单的加法和减法。

Not long ago, researchers learned that four-day-olds could understand addition and subtraction.

不久前，研究人员发现4天大的婴儿能够理解加减法。