1. I do well in maths.

2. My maths result is very good.

3. I have a good achievement at math.

4. I'm good at math.

5. I am proficient in math.

6. I excel in math.

7. I’m good at mathematics.

8. I do well in studying math.

9. She is gifted in math and always gets top marks in her math exams.

这些句子都可以有效地表达你在数学方面的优秀表现。根据具体的语境和需要，你可以选择最适合的句子来表达。