How-To Geek on MSN

You need to know what the tilde (~) does in Excel

The tilde isn't the only sign you need to understand to truly get your head around Excel's inner workings. For example, the ...
Ars Technica

Using Excel's SUMIF (or SUMIFS) with a column of criteria

I keep running into situations in Excel where I want to calculate a conditional sum, but my criterion is something along the lines of "Include cell B1 if cell A1 is a number, likewise B2 and A2, B3 ...