This is the Website for support materials for Mathematics, maintained by Dr. Daniel Nucinkis, EEE. Feedback to: firstname.lastname@example.org
Here are the HELM workbooks in pdf:
They are useful for revision or self-study, from the most basic GCSE material (see "Basic Algebra: Indices" on how to multiply powers of x!) to some fairly high-level topics, see further down! Some are missing, but I hope to get an update soon.