So would i, i've emailed OU and my tutor, my tutor did say it was a higher level, but i'm not sure it would be that difficult (not trying to sound smug), but maths is normally ok once you get the hang of it. I've only been emailing, as i've not had chance to ring them.
Looking at the website it’s basically A/AS level maths. Did you study basic calculus in your HNC? Did you do A-levels?