Do people with ADHD have reasoning abilities and mathematical abilities just like normal people? Do people with ADHD have reasoning abilities and mathematical abilities just like neurotypical people ?
Alright- neurodiversity vs neurotypical label aside, here is the definition of ADHD

http://www.cdc.gov/ncbddd/adhd/diagnosis.html

Here is the best example I could find which demonstrates effect of ADHD on mathematical reasoning:

http://ldq.sagepub.com/content/16/1/6.short

Here is a comparison between learners who are nonverbal, who have aspergers, and then those who have ADHD

http://www.tandfonline.com/doi/abs/10.1080/87565641.2010.494747#.VM1Cynvwo-g