For example, multiplication, we learn to calculate in the form of columns, from low to high, and multiply and add in turn. But India does not think so. I remember once going to the bank to pay the exam fee. We have a total of 12 people, each 1540 rupees. The bank clerk wrote 1540 three times in a row, and immediately knew that the result was 1540 x 12. Instead of using a calculator, he wrote a simple draft of 65,438+02 three times. As for 1 1X, I am even more unclear.