Okay so with the Open Uni you need to build the degree you want, with the modules, so I am looking at what I should select to allow me to easily progress onto a Masters degree with Digital Forensics, Out of the modules on the link below which is most beneficial to learn?
http://www.open.ac.uk/courses/find/computing-and-it <- go to the bottom to see the modules.
Also is taking extended levels of maths a good idea? or a wasted effort?
You are going to need math its the universal language of science. Do you have a bachelors degree already and just for a masters? You are going to need skills in electronic engineering, software engineering, information technology, and skills in troubleshooting all of the above. I am not involved with digital forensics but do low level data recovery as well as build computer systems and have worked in communications. Are you familiar with whats involved with digital forensics or am I stating the obvious. I would say that some criminal law classes would be a good idea as well. You would need skills in all these categories as well as analysis and reporting. Just my opinion Im not a guidance counselor lol. Honestly they probably have a machine and scripts that will do all the hard work. You will just need a degree to get into the door and be able to type run in a cmd window :) The real nerds are the people who design the tools and software that you would be utilizing.