These Foundation modules are designed to develop your problem solving skills and provide an introduction to solving STEP (and STEP-like) problems. Most of the questions are taken from STEP I papers, with some STEP II questions appearing in later modules. The assignments also introduce mathematical ideas beyond the syllabus with lots of opportunities for extra reading.
Even if you are not intending to sit STEP I we strongly recommend that you work through these resources to develop your problem solving skills before attempting the STEP II and STEP III modules. If your university offer only includes a STEP I paper then you should concentrate your efforts on the Foundation modules.
There are 25 Foundation modules, and the intention is that you work through them in order. There are also three collections of STEP questions (one each for pure, mechanics and statistics) which can be found after Assignment 25.