"The value of FMC calculated fuel quantity is set equal to the total fuel quantity from the fuel quantity processor when the airplane is on the ground and there is no fuel flow."
Hope you don't mind if I introduce a little drift. Say you're off to a field with no ground services, and when you get there, you discover that the APU is now inop, so you keep one engine running for the (short) turnaround. After you load the FMC with the new route etc., how is the Totalizer / Calculated fuel affected, since you always had a fuel flow? Suppose you need to refuel?
I know that this is a bit of a stretch, definitely improbable, but not impossible.