Oh I have a good say in that. I luckily got 7 (100) in Canadian grading system in IB HL Math in grade 11. I struggled with English a little bit tho.
I think for me because I did a lot of selfstudy in grade 9 so I am already in a good shape. But I think practice does makes the perfect.
Ask your teacher.
Try teaching your peers if they struggle because it helps you get a better understanding.