If you have studied English, you know that there is no such unit as Wan. There is only one English, ten, a hundred, a thousand, a million and a billion. There are also three digits to count, which is also in line with the international common counting method. For example, 1000000 is written as 100000. In addition, a few thousand is more appropriate. If 10,000 is used, the precision of effective figures is too low. Tens of thousands of words, such as 1w, have no practical significance. Most importantly, fees are generally written in thousands of words.