My brother began to calculate with Rong's star rating from the first volume of senior one. At first, my brother didn't count quickly. He practices Rong's oral arithmetic every day, and his cards make rapid progress. By the time of the final exam, my brother had a little verbal calculation. The questions in the team are very rich, and all kinds of explanations are very well explained. I am happy to use Rong's book to explain my medium height. My brother got 98 points in the final exam.