Hey, to be honest with you, Economics doesn't involve maths that much. I think it is way more related to politics in the sense that you cover government policies extensively. With a 7 at GCSE, an A in A-Level is somewhat ambitious, but if you are passionate about the subject I am sure you can achieve that grade. Economics is one of those A-Level subjects that you pass only by really understanding and interiorising the thought process and how everything flows in an economy. There is no chance that someone who just memorises the concepts will pass. So, if that is your interest lies towards that and you work hard to understand the theories you will be able to achieve an A for sure.