Internal Assessment Math SL

If I got a 7 in my math IA, how could that effect my overall grade in conjunction with the exam score?

IA is really 20% for Maths. It's all about meeting the grade boundary. If you have relatively high scores in P1 and P2, getting 7 in Math IA would help. But I hope you realized that there's a moderation process and it can possibly move down one or two points (different situations every year).. I still think you should just try your best in exam, there's really nothing more you can do with it. 7 in Math IA doesn't mean you can get high score in maths unless you do well in the external exams too, which is worth 80%