This study attempted to find out what differences of the signal sources of brain waves that occurred during performing number sense tasks and mental rotation tasks using sLORETA technology. Twenty students (10 men and 10 women) attending a four-year university in Gyeongsangnam-do were asked to perform six tasks (3 number sense tasks and 3 mental rotation tasks). The EEG brain waves were measured during performing each task and were analyzed by applying to the sLORETA with t-test: paired group test, A-A2=B-B2. The result showed that there were statistically significant differences in theta, alpha, and beta bands between NS1 and NS2, which brain areas included the superior frontal gyrus, the middle frontal gyrus, the inferior frontal gyrus, the superior temporal, the anterior cingulate, the extra-nuclear, and the insula. The anterior cingulate and the superior frontal gyrus were the areas that showed a statistically significant difference between SP2 and SP3 in the gamma band. This study examined the difference in brain activity while performing two different types of tasks by applying sLORETA. It will be expected to deepen the cognitive neuroscience understanding of the mathematics learning process for students.