You've already been linked to my explanation of thought processes, but to answer the most recent question, no. Deaf people are no more gifted in math that what you would find in the general population.
You need to also keep in mind that more advanced skills require such forms of thinking as would likely to be impaired to a degree in a child who has no native language. Unfortunately, with 90% of deaf children being in the care of hearing parents, this is still far too great a number of children. Language delays affect not only language, but cognition, as well.
