Subtraction
With regard to the math puzzle I posed earlier, I will add that when I do something like float a check in advance of actual funds, I go all out, on the principle that if by chance I *do* get slapped with a bounced check charge, I want to make sure I've gotten my money's worth. So I grabbed a whole bunch of things that I can take to work for lunch...and somehow, as I was hustled away from the register, I managed to lose the loaf of whole wheat bread and two bottles of Diet Coke---essentials! Called store and will go back for them later.