Dyslexia is a nickname for "Specific Learning Disability--Reading", listed as 315.0 in the Diagnostic and Statistical Manual-IV (DSM-IV). Most people understand that dyslexia is a persistent difficulty with reading, despite good instruction and at least average intelligence.
There is also a Specific Learning Disability -- Mathematics (315.1, DSM-IV), known as dyscalculia.
The Dyscalculia Forum chose today as the day to raise awareness.
According to the National Center on Learning Disabilities (NCLD):
Dyscalculia is a term referring to a wide range of life-long learning disabilities involving math. There is no single form of math disability, and difficulties vary from person to person and affect people differently in school and throughout life.
Here's an index page on math and LDs from NCLD. Here's LDOnline's index page on math disabilities. Here's an overview of math disabilities in children from SchwabLearning. Anna J. Wilson's Dyscalculia Primer and Resource Guide
Dyscalculia Dyscalculia: Not Just Troubles with Math Raising Awareness of Dyscalculia