Attitudes toward math (ATM) predict math achievement. Negative ATM are associated with avoidance of math content, while positive ATM are associated with exerting more effort on math tasks. Recent literature highlights the importance of considering interactions between ATM and math skill in examining relations to achievement. This study investigated, for the first time, the effects of the interaction between math skill and ATM on the neurocognitive basis of arithmetic processing. We examined the effect of this interaction using a single-digit multiplication task in 9- to 12-year-old children. Results showed that higher math skill was correlated with less activation in the left inferior frontal gyrus (IFG), and positive ATM were correlated with less activation in the left IFG. The relation between ATM and the neural basis of multiplication varied depending on math skill. Only among children with lower math skill, positive ATM were associated with greater activation of the left IFG. The results suggest that positive ATM in low-skill children might encourage them to more fully engage the neurocognitive systems underlying controlled effort and retrieval of multiplication facts. Our results highlight the importance of examining the role of both attitudinal and cognitive factors on the neural basis of arithmetic development.