First off, It's always bugged me that there is no equal sign on the
number pad of my keyboard, it just seems like it's something that
should be included in that set of keys.

The other day I found that you can use + or - instead of
= to perform simple calculations. For instance if you
wanted to find the solution to 15*30 you could type +15*30 instead of
=15*30. The same is true with -, so if you type -2+4 you get 2.
Also if you type - instead of = for more complex functions, Excel
automatically adds that equal sign and negates the answer.

*This may not seem like a big deal and I'm not sure if anyone else has
ever posted it (I didn't come up with any search results) but since I
stumbled across it a couple days ago I've found it pretty
useful/interesting so I just wanted to pass it along.