How do maths modules work?

I'm doing the OCR MEI exam board for A-Level. (I'm about to go into Year 12.)

How do the modules work out for a student studying Mathematics and Further Mathematics?

I'm guessing C1, M1, S1 and D1 are all compulsory and so is FP1...

But what else is mandatory and what else is optional?

C1-4 is not optional and must be part of the A Level Maths, along with 2 applied modules, so you could do M1 & M2, M1 & S1, M1 & D1 etc. along as you do the '1' module before doing the '2' module.

For FM, FP1-2 is compulsory for EDEXCEL, I'm not too sure about OCR MEI, sorry. So, the rest of the FM A Level is composed of optional modules, either more pure (highly recommended) and then some more applied!

Adding to what jordan said at the end, for OCR, FP1 and one of FP2 and FP3 is compulsory, so you could do FP1 and FP2, or FP1 and FP3 or FP1, FP2, and FP3 as neither module requires knowledge from the other.

I thought FP2 was compulsory for A2 with MEI

C1-4 is not optional and must be part of the A Level Maths, along with 2 applied modules, so you could do M1 & M2, M1 & S1, M1 & D1 etc. along as you do the '1' module before doing the '2' module.

For FM, FP1-2 is compulsory for EDEXCEL, I'm not too sure about OCR MEI, sorry. So, the rest of the FM A Level is composed of optional modules, either more pure (highly recommended) and then some more applied!