Activation maps show greater activity during Exact Addition compared to the control task in the left superior frontal sulcus, posterior medial frontal cortex, right central sulcus, left anterior and posterior HIPS, right posterior HIPS, bilateral precuneus, left precentral sulcus, bilateral activations in the dorsolateral prefrontal cortex, left cingulate gyrus, right and left head of caudate, right thalamus, right anterior insula, right and left deep cerebellar nuclei, and right cerebellar cortex.