Researchers now sometimes use the terms "math dyslexia" or "math learning disability" when they mention the condition. Cognitive disabilities specific to mathematics were originally identified in case studies with patients who experienced specific arithmetic disabilities as a result of damage to specific regions of the brain. More commonly, dyscalculia occurs developmentally as a genetically linked learning disability which affects a persons ability to understand, remember, or manipulate numbers or number facts (e.g., the multiplication tables). The term is often used to refer specifically to the inability to perform arithmetic operations, but is also defined by some educational professionals and cognitive psychologists such as Stanislas Dehaene and Brian Butterworth as a more fundamental inability to conceptualize numbers as abstract concepts of comparative quantities (a deficit in "number sense"), which these researchers consider to be a foundational skill upon which other mathematics abilities build. Symptoms of dyscalculia include the delay of simple counting, inability to memorize simple arithmetic facts such as adding, subtracting, etc. There are few known symptoms because little research has been done on the topic. Etymology
The term dyscalculia dates back to at least 1949.Dyscalculia comes from Greek and Latin and means "counting badly". The prefix "dys-" comes from Greek and means "badly". The root "calculia" comes from the Latin "calculare", which means "to count"; it is also a cognate of "calculation" and "calculus". See also
References
Further reading
Abeel, Samantha (2003). My thirteenth winter: a memoir. New York: Orchard Books. ISBN 978-0-439-33904-9. OCLC 51536704. Ardila A, Rosselli M (December 2002). "Acalculia and dyscalculia" (PDF). Neuropsychol Rev.
Common symptoms of dyscalculia are having difficulty with mental math, trouble analyzing time and reading an analog clock, struggle with motor sequencing that involves numbers, and often counting on fingers when adding numbers. Common symptoms
Dyscalculia is characterized by difficulties with common arithmetic tasks. These difficulties may include:

Difficulty reading analog clocks
Difficulty stating which of two numbers is larger
Sequencing issues
Inability to comprehend financial planning or budgeting, sometimes even at a basic level; for example, estimating the cost of the items in a shopping basket or balancing a checkbook
Visualizing numbers as meaningless or nonsensical symbols, rather than perceiving them as characters indicating a numerical value (hence the misnomer "math dyslexia")
Difficulty with multiplication, subtraction, addition, and division tables, mental arithmetic, etc. Inconsistent results in addition, subtraction, multiplication and division
When writing, reading and recalling numbers, mistakes may occur in the areas such as: number additions, substitutions, transpositions, omissions, and reversals
Poor memory (retention and retrieval) of math concepts; may be able to perform math operations one day, but draw a blank the next; may be able to do book work but then fails tests
Ability to grasp math on a conceptual level, but an inability to put those concepts into practice
Difficulty recalling the names of numbers, or thinking that certain different numbers "feel" the same (e.g.