Actually, there's no direct answer to your question because it
depends on many factors. For one, you have to realise not everyone
holding an EE degree actually specialises in the same thing - some
will choose to specialise in things like semiconductors/fabrication
processes, while others might specialise in signals and
communication systems. Hence, the maths required for your area of
specialisation could be quite different. However, I believe, by and
large, most engineering courses will still require an extensive
knowledge of maths and the maths topics covered at the basic
level(your foundation years prior to your specialisation) are
pretty similar across the board.
To my knowledge, I know advanced topics(by that, I mean most things
you probably wouldn't have covered by your A levels) like linear
algebra, laplace transforms, fourier series and transforms are
integral aspects of EE course (basically, it's highly unlikely, if
not completely impossible, that any college would conduct an EE
course without teaching these topics). That aside, some rudimentary
programming involving OOP(probably C++ or java) and assembly
languages will also be a key component of your education. I suppose
you could go read up the abovementioned maths and programming
topics to see if they're your cup of tea... 
Having said that, I think the difference really comes from what you
do later on. For the American system, if you do not take a
proactive approach do your learning and expect to be spoon-fed or
just learn the minimal scope(ie.only what's directly taught), you
might still get by to complete your degree, but chances are you'd
struggle when you start working as an engineer. Hence, if you're
the sort who needs extensive spoon-feeding or people telling you
what to do(ie.no initiative to learn beyond what is taught on your
part), the British system might be better in the sense that the
scope of what is taught is considerably more than the American
system. 
Hope that helps.
