Launch bc using the -l or --mathlib option to get 20 decimals of precision and load some basic math functions. I have this as an alias in my .bashrc, so I don't need to do this every time I launch the program.
To clarify: this is not Emacs. Instead, it is a text editor that features improvements over the built-in editor. It was partly written by Carsten Dominik (creator of Org mode), who is an Emacs user. Some features were inspired by Emacs, but the similarities end there.