When your student feels they are so different from others with their learning disability, no worries, we are all different, see the list with no less than 34 types of diversity recognized in any workplace.
Simply performing poorly in maths does not necessarily mean that a student has a specific learning disorder in this area. There are a number of reasons why an individual may find it more challenging to develop their numeracy skills
If you are already familiar with Dyslexia, it is easier to understand the things that happen when you have Dyscalculia. Although they are very different, here is an overview of where you see how it affects people similarly.