I think I over-do my signaling on my answers on exams
What are you supposed to accomplish by signaling like that?
I'm looking for a good reason not to do the exam
All you have to know is to do your best no matter what, because these exams will matter for your grade and future. Instead of getting out of them, try studying.
But I don't want to study!
There are a lot of things people don't want to do as they get older. It's better to do well now as a child in order to set up a good foundation to do well as an adult. That way life will offer up more opportunities and make things slightly easier.