Scribbling notes, shopping lists or messages on the back of an envelope can still be useful, quick and portable.

手写笔记、购物清单或留言仍然是比较有用的、快捷的和便携的。

Holmes glanced over some notes which he had scribbled upon the back of an envelope.

福尔摩斯瞥了一眼他在信封背面潦草地写下的一些笔记。

ROSS MCNUTT: ... this one stuck and we sort of drew this out on the back of an envelope.

罗斯·麦克纳特：… … 这个卡住了，我们把它画在信封背面。

I think my favorite part of this one is that it looks like it was sketched on the back of an envelope.

我认为我最喜欢这个的部分是它看起来像是在信封背面画的草图。

We've got Measurement by Paul Lockhart and Maths on the Back of an Envelope by Rob Eastaway, who I have to assume is British.

我们有保罗·洛克哈特 (Paul Lockhart) 的《测量》和罗布·伊斯特威 (Rob Eastaway) 写的《信封背面的数学》，我猜他是英国人。

Being able to reconcile all of these different observations is not the kind of thing you can do on the back of an envelope, even if you have a really big envelope.

将所有的观察值协调到一起，不是那种你可以在信封背面做的事情，即使你有一个很大的信封。

Maths on the Back of an Envelope was a lot more utilitarian, taking problems you might find in the daily world and figuring out how to get answers fast.

信封背面的数学更加功利，它解决了你在日常生活中可能发现的问题， 并弄清楚如何快速获得答案。