I'm brewing an oatmeal stout tomorrow and have had sporadic efficiency numbers from my last 6 brews. 5 out of my last 6 all grains have had a preboil reading of at least .010 less than where they needed to be. This time around I'm preparing by having some DME handy in case I don't hit my numbers. Just wondering what the math is for how much DME is worth to gravity points. So say I'm shooting for a preboil of 1.065 and I hit 1.055, I would use ______ cups of DME.