I have interests separate to skills. I'd incorporate skills into your work experience. Further, detail the modules you studied for your maths degree and any extra curricular activities? Play in a team? Member of a society? Did you have to do any presentations? Represent your uni at anything?
Maybe put something in interests to show your human side. Do you seek challenges and broaden your horizons outside of education and work? See you have powerlifting - that is a good start. Maybe you have taught yourself a language or skill? Hobbies such trekking, yoga, astronomy, making model aeroplanes...anything... Makes you sound far more interesting and unique.
Also, I'd change "Despite my job title I often to run the front-end of the store including checkouts, kiosk and self-serve tills, and consequently deal with any problems as they arise."
Remember, a CV should be positive and selling your best points. This sounds like you have a negative opinion of your current role. For every point think skills, responsibilities and achievements. What skills did I use and what did I achieve? Think leadership, management, deadlines, achieving targets, challenges etc.