Microsoft Excel is WRONG!!! Beware...
That's a good resource link you posted. It illustrates the point exactly. I understand that Excel is not a "heavy math" program, but something as simple as the order of operations should be followed.
Try this one on for size - did you know that the following is true according to Excel:
5^2 - 5^2 = 0
-5^2 + 5^2 = 50
Does that make any sense? I know what they're trying to do, but it just doesn't fly...