What you said is very reasonable, so I want to say something from the heart. Mathematics is a rare and confusing subject. I don't know what's the use of learning mathematics, even my predecessors don't know. Many mathematical geniuses have switched to psychology. Why? Because mathematics is a subject with no practical value, the number 1/3 is actually an unfinished number. 1/3*3= 1 is due to rounding, but the premise is that 1 should be divided by 3 first. If 3 is divided by 3 first, it is equal to 1. It is said that studying mathematics. For example, if you insist that 1=0.9999 cycle, then I ask you 1-0.9999 cycle = 0.0... 1, do you admit it? I can't tell you the reason, but I'm sure that all kinds of calculation methods that human beings are proud of now will be overthrown in the future, maybe a long time later ... This question you raised is very valuable, maybe I'm wrong now, but I advise you not to dwell on such problems again. I spent several days studying several physical and mathematical problems similar to this one, but all in vain. Rarely confused ... Out of this passive society, only by accepting, learning and remembering can we get the so-called power and money. Hehe, I seem a little impulsive. You are one year older than me, and I'm a little embarrassed ... I want to be your friend, okay? Because this question is too valuable. ....