Im in year 12 atm and for my GCSES recieved 9 A* (inc further maths and maths) an A and 2 B's (french and Pe). I am currently studying Further maths, maths, physics and economics at AS level and am likely to drop physics after AS. I think i want to do mathematics at university, maybe joint with economics and would like to go to a top university either in the UK (oxbridge/LSE/UCL/imperial etc) or in America (harvard, MIT etc) . My question is if there is anything i should be doing now, aside from focusing on achieving the best grades possible, to boost my chances to get into the uni i want. Is work experience important/neccessary? What sort of work experience is beneficial because i have no job ideas yet i just like doing maths? Any other advice about university or my subjects would be helpful.