It's dyscalculia.
The curse of math instructors everywhere.
A few years ago, students at the community college, where I taught, petitioned to have math removed from the list of courses that were required for a degree. Part of the reason, they argued, was that one student claimed that he shouldn't have to take math because he had dyscalculia.
(Dyscalculia is like dylexsia, except that it makes it harder for people to do arithmetic. )
The math instructors argued that they weren't going to eliminate requirements for a "fictional disease."
Now, it appears that miscalculations do have a biological basis and researchers at University College London have been able to show it.
Using fMRI, the authors found differences in brain activity, in a specific region of the brain, between people with dyscalculia and people without the condition.
I'm willing to bet that in the next few years, we clone the gene. But can you calculate the probability?