rough calculation造句

1、My rough calculation is that such a program would boost consumption by Rmb 500 billion.
我简单计算过，这个计划可以刺激5000亿元的消费。

2、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。

3、I make some rough calculation on the back of an envelope.
我的信封背面大概算了一下。