我快速计算了一下，看看我们是否负担得起。

I did a quick ___calculation to see if we could afford it.

一个简单的计算：大象在动物园的生活空间大约是500平方米。

Just a simple ___calculation: the living space an elephant has got in a zoo is about 500m2.

工程师为桥梁设计做了一个精确的计算。

The engineer made a precise ___calculation for the bridge design.