Yes, that's the common parlance. I can understand bambam's point, but you can't replay the games that have already been played. You have to get back to .500 one game at a time, and you can do it only by winning future games, not by changing the results of past games.
Logic/math have no place in this discussion. The flawed parlance has been part of the game forever and it's not going to change, so go with it. Everybody who cares understands it, and that's all that matters.
I mean a "300 hitter" is actually only hitting three 10ths.