×10{{{1}}}

The {{e}} template is intended to facilitate and make uniform scientific notation numbers. To render

3.14×10−12

instead of writing:

3.14×10<sup>−12</sup>

you can write:

3.14{{subst:e|−12}}

which yields that same wikitext, and is therefore rendered the same.

See also m:Template:e (talk, backlinks, edit).