Currently Maths GCSE, as I understand it, does not include basic finance (e.g mortgages, credit cards, loans etc), however it does include subjects that most people are unlikely to need (e.g quadratic equations).
My proposal is that we split Maths into two subjects so we have
1) “basic” maths which would be mandatory and includes the basic elements of the current maths curriculum, removes the more “exotic” material which is only really needed if you wanted to progress in maths, science, engineering…, but now includes material relating to (personal) finance
2) “additional” maths which would be optional and would contain the more “exotic” material required for those who want to progress in maths, science, engineering. This could now contain more of this type of material than currently in the maths curriculum.
This split is perhaps similar to that currently in English where English language is mandatory and English literature is optional.
The above would provide all children with a level of education in finance.
The “basic” maths would be more relevant to the children taking it perhaps making them more engaged with that subject.
The “additional” maths should be able to provide more education in the slightly more”exotic” areas of maths which would make those pupils better prepared for the maths in the related subjects. And as only pupils wanting this subject would take it, there might be an improved level of engagement in those lessons.