It's a shortcut way to convert a text number into a number value. HTH
Otto
"uw805" wrote in message
...
I feel I should know the answer to this, but I don't, and I can't find it
in
excel help.

What does "--" do in a formula?

I've seen it used in a few formulas (sumproduct & mmult specifically), and
I've even used it myself when advised to do so, but I don't quite
understand
what it does. Can someone explain?

Thanks.