How hard is it to get an A in maths GCSE?

my mocks are going on right now i have my first math exam tomorrow. I am doing higher tier but i'm not sure how difficult the paper will be. i have done a few practice ones but they have varying difficulties and not all the same topics. i am in set 2/7 in my year so i'm not bad at maths but i haven't learnt all the topics yet. can anyone give me an idea of what to expect?

Freethinking Liberal

One of the problems for GCSE Maths is the structure of education. Apart from maths, GCSE is about just facts. There is little in the way of manipulation of the information. Maths on the other hand, is mostly about manipulation of data. So, with maths it vital to practice with data. To do this, buy the study guides for your exam body. Do the specimens over and over again until you can do them in your dreams... then you will get an A*