I am Mathrmatics Olympiad expert, Mathematics Olympiad problems are one of the hardest in the world, for example IMC 2021 (the 28th international competition for university students) there were problems which only 1 or 2 students solved (I was one of them). Mathematics is the same eveywhere, wherether it is A level or IB, the goal is to find a creative and elegant solution. I solved many past papers in IB level in A level mathematics and physics, I can assure you I will teach mathematics and you will excel everywhere, you will be able to solve any problems.