You will need one that handles natural logarithms (the key).
To do square roots using the calculator program that comes with Microsoft Windows, use the "View" menu to set the view type to "Scientific", click the "Inv" checkbox, then use the "x^2" key.
Secondly it gives a bit of "slice of life" illustration of how the concept relates to the world of the novel. They reveal themselves to nobodies who care."The point of this website is to allow a science fiction writer or game designer to get the scientific details more accurate.
Thirdly I tend to use novels that I personally think are forgotten and under-rated classsics, hoping you will be intrigued enough to look up a copy of the novel. It is also to help science fiction readers and game players to notice when the media they are enjoying diverges from scientific reality. This web site might not be an adequate crib-sheet for media science fiction, but I'm doing my best.
If it survives both, I will incorporate your contributions.