In *The Romance Resonance* he read a data table in a text book wrong

> **Sheldon**: This is the very copy of The Handbook of Chemistry and Physics in which I looked up the reaction rates of mendelevium and…
>
> **Amy**: And what?
>
> **Sheldon**: No. No, no, no, no.
>
> **Amy**: What’s wrong?
>
> **Sheldon**: I’ve made a horrible mistake.
>
> **Amy**: What are you talking about?
>
> **Sheldon**: This table, it’s in square centimetres. I read it as square metres. You know what that means?
>
> **Amy**: That Americans can’t handle the metric system?
>
> **Sheldon**: Amy, I was off by a factor of 10,000.

[script source](https://bigbangtrans.wordpress.com/series-7-episode-06-the-romance-resonance/)