I don't think you're going to find a simpler one-stop-shop implementation of curve arithmetic than vbuterin's code.
It looks like it is a simple gx times private key Mod P to get the public x part.
I can't tell if you're referring to
http://en.wikipedia.org/wiki/Elliptic_curve_point_multiplication or if you're confusing point-multiplication with `*` in `6 * 2 = 12`.
`base10_multiply` is recursively applying the `base10_add` function. It's all pretty much laid out there for you, although it helps to know that `inv` is an inverse mod function.
If you're having difficulty understanding the math, then it probably means you need to zoom out and get a higher level understanding of elliptic curves and some dependent nodes along that talent tree. If you're using Mathematica, then surely there are examples of curve math out there already described for you in the semantics of Mathematica so you don't have to translate Python.