A Head for Figures

It has long been debated whether the ability to solve mathematical problems depends on language. In this issue, Dehaene et al. show that exact calculations involve linguistic representations of numbers and are controlled by the speech-related areas of the left frontal lobe in the brain. In contrast, approximate calculations are language-independent, relying on visuo-spatial representations of numbers controlled by the left and right parietal lobes. In an accompanying Perspective, Brian Butterworth discusses these findings and postulates that the parietal lobes may also be involved in finger counting, an almost universal stage in the learning of exact arithmetic.