I did "Intro to Astro" last time it was offered.
I've signed up again not to improve my results (over 90% but under 100%) but to see how much Ronen has changed it and offer a hand where needed. They might be after volunteer TAs.
The math isn't trivial but it isn't complex. I recommend you install "R"
http://www.r-project.org/ and "MathJax"
http://docs.mathjax.org/en/latest/installation.html to make life simpler.
R is intended for statistical analysis but it makes a great calculator. We made extensive use of in in the ANUx courses.