Through fortuitous events I have obtained a masters degree in an engineering field with relatively little prior mathematical knowledge (a C grade GCSE over ten years ago). Encountering numerical and statistical problems now often requires me to regress back and learn topics I would have covered in my earlier academic career, had I taken A-Levels or undergraduate mathematics.
Clearly, starting with the current GCSE/A-Level syllabus would be useful, but can anyone offer advice regarding whether it would be worth actually taking the exams and obtaining the (in this case) A-Level qualification?
Edit: Recognizing this might be too UK-centric (my apologies) - for clarity GCSE/A Level would refer to pre-university education elsewhere.