Most domestic students are only good at arithmetic, which is far from modern mathematics. For example, my own arithmetic level is not bad among China people. I can use multi-digit addition and subtraction and double-digit multiplication to do oral calculation quickly, and I can also use double-digit to calculate high-digit without a pen. For example, every time I read the paper, my teaching assistant holds a calculator and presses it one by one. I always take a look at it and get the total score directly. Make at most one or two mistakes in a class. However, many people don't do addition, subtraction, multiplication and division or simple calculus as fast as me. When it comes to doing mathematics, they have a wide range of ideas and knowledge. To be honest, their research is better than mine. An ordinary China student, compared with ordinary addition, subtraction, multiplication and division, and the basic concepts of numbers, is indeed better than those who rely heavily on calculators in Europe and America, but good arithmetic does not mean good mathematics. When it really reaches the level of modern mathematics and needs to be highly abstract, most China students who are fluent in addition, subtraction, multiplication and division behave like that, to be honest, but they are really not outstanding.