Decreased mathematical ability due either to a learning disorder or damage to the brain.
Example: A professor of mathematics, under treatment for brain trauma after a car accident, discovers he can no longer figure a fifteen percent tip.
Here is a great website that allows people to see a comprehensive list of all of the symptoms associated with dyscalculia, it also has treatment options and prevention methods:
Last updated: 17 Jul 2016
Last reviewed: By John M. Grohol, Psy.D. on 17 Jul 2016
Published on PsychCentral.com. All rights reserved.
Fournier, G. (2016). Dyscalculia. Psych Central. Retrieved on December 16, 2017, from https://psychcentral.com/encyclopedia/dyscalculia/