Cathy did a rough calculation.

凯茜作了一个粗略的计算。

She did a rough calculation.

她做了一个粗略的计算。

I make some rough calculation in the back of an envelope.

我在信封的背面做了一个粗略的估算。

From rough calculation, we can see that we have no profit.

粗略计算后可以看出我们无利可图。

Manabe also worked up a rough calculation for the effects of clouds.

Manabe还开始对云层的影响进行了粗略的分析。