This sounds a lot like Dyscalculia, which is the "numbers" version of dyslexia.
Here's some info I've retrieved about Dyscalculia
Some symptoms of dyscalculia are:
Normal or advanced language and other skills, often good visual memory for the printed word.
Poor mental math ability, often with difficulty in common use of money, such as balancing a checkbook, making change, and tipping. Often there is a fear of money and its transactions.
Difficulty with math processes (e.g., addition, subtraction, multiplication) and concepts (e.g., sequencing of numbers). There is sometimes poor retention and retrieval of concepts, or an inability to maintain a consistency in grasping math rules.
Poor sense of direction, easily disoriented, as well as trouble reading maps, telling time, and grappling with mechanical processes.
Difficulty with abstract concepts of time and direction, schedules, keeping track of time, and the sequence of past and future events.
Common mistakes in working with numbers include number substitutions, reversals, and omissions.
May have difficulty learning musical concepts, following directions in sports that demand sequencing or rules, and keeping track of scores and players during games such as cards and board games.