Abstract: We believe that children's intelligence can be raised to a certain extent by increasing the efficiency of the brain activity through mental exercise. In our experiment, a series of problems were given to children as arousals for their brain activities. The results obtained from two successive experiments support the author's viewpoint This paper is a report on the second experiment.The experiment was held in a middle school. A first-year class of 42 students and a fourth-year class of 44 students were used as experimental classes while another first-year class of 43 students was used as the control class. The two experimental classes were asked to solve one problem within ten minutes each morning in their own classrooms. 64 such exercises were done during the whole semester.As a result, the mean IQ of the first-year class increased 5 points, and that of the fourth-year class increased 6 points, while that of the control class remaind the same.

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