What does Kangshu stand for?

The number Kang stands for 7. My answer to this question is that health and happiness stand for 2 178. First of all, if a product of four digits is still four digits, then its thousand digits can only be 1 or 2. In this problem, the first number multiplied by 4 is the mantissa of the four-digit product, so it can only be an even number. In this way, health can only be the number 2 and happiness is the number 8. Similarly, we can analyze that Kang and Kuai are 1 and 7 respectively. Then health and happiness represent 2 178. This figure means that health is the most suitable. Because 6 means smooth, and 666 means smooth. When everything goes well, a person will feel very comfortable and in a smooth mood. If you are in a good mood, you will always laugh and be happy, and naturally you will not be angry, angry, irritable and painful. Therefore, the number Kang stands for 7.