AS/A-Level options

I've already chosen 4 subjects but I need help deciding on the 5th. 5 Subjects because I'm doing one as an external candidate as it doesn't fit into the school timetable and the next nearest sixth form is over an hour away by bus. My sixth form is forcing me to take 4 subjects in school (excluding general studies) for at least the first couple of weeks which explains why I need to pick a 5th subject.
So far I've chosen biology chemistry and Spanish (physics at home). I was wondering how hard is it to take the sciences without maths? Is it a really bad idea or would I be able to manage with doing a bit of extra maths work when needed? I know everyone has different opinions about it but I just want a general idea.
For my 5th option I can choose from French, geology, or maths.
All of the sciences are OCR A, maths and the languages are AQA.

If anyone has taken these subjects with the same exam boards, do you have any tips/advice?
Thanks in advance.

I've heard from my friends, you need to be comfortable with the concepts of straight lines, gradients, correlation etc also rearranging equations and chemistry at A2 will involve logarithms, I'm not sure on the full details but you can use www.m4ths.com to find some GCSE/A-level tutorials if you get stuck. Personally though I'd chose maths as it compliments the sciences quite well and also is a very respectable A-level. (Or AS-level)

I do all the sciences and maths and I can say that maths was helpful for physics at times However, one of my friends did all three sciences and history and didn't struggle really. It's only really when you get to A2 that it may be a bit of a hindrance, with logarithms something cropping up in Chemistry and Physics and other topics I mean, I would recommend it in all honesty, but if you really don't want to don't worry too much, extra maths outside of it for A2 should suffice if you put enough effort in

Thank you, especially for the link!

Ahh right, thank you! I'll do a bit of physics work over the summer and see how it goes - I'll probably end up taking maths like you did haha
It's just that I did find it a bit boring at GCSE but hey, opinions do change