STEP

STEP is a challenging examination. However, they are taken after A Levels (compared to late October/early November of Year 13 for MAT and TMUA) so you have more time to prepare and are a better mathematician (hopefully!) by that point. In addition, there is a selection of questions and you don't need to answer "that many" in order to achieve a Cambridge offer.

Cambridge Maths offers are typically based on STEP 2 and STEP 3. STEP 2 is based on A Level Maths and AS Further Maths and STEP 3 on both full A Levels. However, you might want to consider starting your preparation with some STEP 1 problems (just based on A Level Maths) and maybe even entering that exam to help you 'get into the zone.' Part of the recipe for success with STEP is in choosing the right questions for you and that comes with plenty of past paper practice. It should also be mentioned that, as all the questions are longer than A Level, you should have a higher threshold of thinking 'this seems a bit messy/long-winded' for instance, long algebraic expressions.

Another critically important aspect of STEP is working at it over a long period of time. Even though at the end of Year 12 or beginning of Year 13 it seems a long way away, the time quickly passes when you have to write a Personal Statement, attend interviews, complete mock examinations and then prepare for A-Levels. The sooner you start preparing, the better, but it expect that it will be hard in the beginning and don't let that put you off!

Below is a link to the Stephen Siklos (long-time Chief Examiner for STEP) book which is a must-read. There also a book which has lots of nice extension problems for Further Maths (useful for STEP 3 in particular), a link to an online STEP course and MEI's collection of worked STEP solutions which are often much easier to understand than the official mark-schemes which are written for marking rather than learning. There is also a document about what is called the "half-angle substitution" which is no longer on the A Level syllabus but might still form the basis for some STEP questions where they expect you to work it out on the fly.