back-of-the-envelope
成語所屬單字envelope
back-of-the-envelope — 慣用語
1. Describing a calculation, estimate, or plan that is done quickly and roughly, wi
1.慣用語
釋義
粗略的；快速的（計算或估算）
Describing a calculation, estimate, or plan that is done quickly and roughly, without detailed analysis or precise data.
例句
We did a back-of-the-envelope estimate and found the project would cost around fifty thousand dollars.
A back-of-the-envelope calculation suggested the trip would take about three hours by car.