Short-term memory has often been found to play a major role in children's arithmetical skills. However, Bull and Johnston (1997) found that when differences in reading skills were controlled for, short-term memory, specifically the functioning of the articulatory loop, did not represent a fundamental deficit for children of low mathematical ability. This study examined the role of other working-memory mechanisms in arithmetical skills, namely the central executive, using the Wisconsin Card Sorting Test (WCST), and the visual-spatial sketch pad, using the Corsi Blocks. Results showed that children of high and low mathematics ability differed significantly on WCST measures after controlling for differences in reading ability and IQ but did not differ in visual sequential memory. Correlation analyses revealed a significant correlation between arithmetic performance and perseveration measures from the WCST. The implications of this result are discussed in terms of central-executive functioning and related cognitive and behavioral difficulties.