My son yoyo began to learn official document mathematics at the age of 18, and the effect was good, which was faster than kindergarten mathematics class. At first, I was full of doubts. After studying for a year, I summed up its advantages: 1, individual counseling is more suitable for children than group teaching; 2. Step by step, with reasonable difficulty gradient; 3, emphasizing the time and speed of homework is conducive to cultivating children's good study habits; 4, the effect is outstanding, which is obvious in about 3 months; 5. Use the "counter" strategy to count from positive to negative, and add and subtract. I have done so much publicity for official document mathematics. Send me some advertising fees after the Chinese New Year!