Borderline intellectual functioning is a neurodevelopmental condition characterized by an intelligence quotient (IQ) in the range of 70-85. The present study aimed to investigate the mathematical abilities and the working memory of students with borderline intellectual functioning (BIF). The sample group included 10 year-old students with BIF (n = 85) and with average non-verbal IQ (n = 45). The children were assessed in non-verbal intelligence, numerical ability and working memory. Our results showed an impairment of mathematical skills, especially in the operation tasks, and working memory in children with BIF, compared to typically developing peers. Generally, their skills seemed to be consistent with intelligence scores (WOND and AWMA scores ≥ 70). In some cases, children with BIF could have mathematical difficulties (WOND < 70). In general, they showed visuospatial short-term memory and central executive subsystem more damaged than non-verbal intelligence while the verbal short-term memory was similar to the IQ.