Is A level maths hard

Im uk and year 10 but im doing my maths gcse this year and im working at an astar getting around 94-98 on past papers,and in year 11 im studying additional math matics which has ucas points i think, im just wonderig how hard is a level maths(further) will i have to attend every lesson and work hard or will it be a breze, my maths tracher said i shpuld pass it with out a sweat but online it says its hard, any questions