ELI5: Is my ability to do math in my head not normal?

Hi people! Is my ability to do math in my head not normal, or ability to do math on paper? In other words, ability to do math on paper is just normal not different, but ability to do math in my head is also normal but a bit different? Is it ability to do math on paper more normal and just math in my head "okay"? So I am having a bit trouble with wording... hopefully other top level comment here might be able to explain it better.