• Adults with epilepsy reported difficulties in both basic and secondary math skills. • Difficulties in working memory accounted for a significant amount of variance in math outcomes. • The limited capacity storage component of working memory was detrimental for poor math. • Difficulties with mathematics may be comorbid with epilepsy, rather than epilepsy related. Mathematics encompass a variety of skills, broadly grouped into basic numeracy to complex secondary mathematical skills. In children with epilepsy difficulties with mathematics are common and related to a multicomponent working memory capacity. Little is known about mathematical skills of adults with epilepsy in daily life. Hence, we aimed to compare basic and secondary mathematical skills of adults with epilepsy to controls, examine relations between mathematical skills and working memory, and explored relationships between mathematical skills and epilepsy variables (age of onset, seizure frequency, and anti-seizure medication). Eighty four people with epilepsy and 86 healthy controls completed questionnaires on their subjective experience of using mathematics and working memory skills in daily life: The Dyscalculia Checklist (DC) and Working Memory Questionnaire (WMQ; including attention, storage, and executive scales), respectively. Questionnaires also collected demographic and epilepsy variables. Adults with epilepsy reported greater difficulties in basic and secondary mathematical skills on the DC compared with controls. Only one epilepsy variable, a younger age of epilepsy onset, related to higher DC scores (greater mathematical difficulties), but was not significantly related in regression analyses. Instead, the WMQ explained 33% of the variance on the DC; the poorer storage and attention (but not executive) on the WMQ were associated with the higher DC score, when demographic and epilepsy variables were accounted for. Adults with epilepsy reported significant difficulties with mathematics in daily life, which were not explained by epilepsy variables but by poor working memory. While our findings suggest that daily difficulties with mathematics may be comorbid with epilepsy rather than epilepsy related, it is important to be cognizant of mathematical difficulties experienced by patients with epilepsy as they have potential to impact understanding of numerical information provided in patient care, such as risks associated with different epilepsy treatments. [ABSTRACT FROM AUTHOR]