acalculia /a′kalko̅o̅″lyə/ [Gk, a, not; L, calculare, to reckon] , the inability to perform simple mathematic calculations the patient previously knew. Commonly seen in neurological disorders, it is assessed by having a patient count forward or backward or do mental addition or subtraction. See also agraphia, constructional apraxia, dementia, finger agnosia, Gerstmann’s syndrome.
