Granted. Due to your vague description of a 'halfling', you are given a half fish-half hamster servant that is pretty much incapable of doin anything. I wish for the ability to pay attention better.
So. I've been trying my hand at calculating the Delta-V of my craft rather than using guesswork to get to celestial bodies. I am hindered by one part of the formula: Natural Logorithm. What is it and how is it found?