MATHEMATICS  is a skill which you develop over time. So don't worry about this. There is nothing you called Average. It may be the case, that you have not pushed yourself that much. See the interest is the main factor for a student who want to pursue a career in anything. So if you are interested in Mathematics just go for it. With time you will get to learn a lot from the subject. See not everyone is a master of all topics of Mathematics. So pursue your interest and you will find yourself to enjoy the subject as well as you will score great in the subject.

For more information regarding BSc in Mathematics consider the link below:

https://www.careers360.com/courses/bsc-in-mathematics

I hope this helps. Wish you a great eve!