How much water should be added to a 6 oz can of tomato paste to yield an 8 oz can of tomato sauce?

Well, darling, if you want to turn that puny 6 oz can of tomato paste into a big shot 8 oz can of tomato sauce, you'll need to add 2 oz of water. It's simple math, just mix that paste with some water until you reach the desired volume. Voilà, you've upgraded from paste to sauce in no time!