0 can be said to be the earliest number that human beings have come into contact with. Our ancestors only knew nothing and existence at first, and none of them was 0, so 0 isn't it? I remember the primary school teacher once said, "Any number minus itself equals 0, and 0 means no quantity." This is obviously incorrect. As we all know, 0 degrees Celsius on the thermometer indicates the freezing point of water (that is, the temperature of ice-water mixture at standard atmospheric pressure), and 0 is the dividing point between the solid and liquid state of water. Moreover, in Chinese characters, 0 means more as zero, for example: 1). Decimal number. 2) the quantity is not enough to meet the demand of a certain unit ... At this point, we know that "no quantity is 0, but 0 not only means no quantity, but also means the difference between solid and liquid water, and so on."

"Any number divided by 0 is meaningless." This is a "conclusion" about 0 that teachers from primary school to middle school are still talking about. At that time, division (primary school) was to divide a copy into several parts and figure out how many there were in each part. A whole cannot be divided into 0 parts, which is "meaningless". Later, I learned that 0 in a/0 can indicate that a variable with zero as its limit (the absolute value of a variable is always smaller than any small one in the process of change) should be equal to infinity (the absolute value of a variable is always greater than any large positive number in the process of change). This leads to another theorem about 0: "A variable whose limit is zero is called infinitesimal".

"Room 203 105 in 2003", although all of them are zeros, they are roughly similar in appearance; They have different meanings. 105 and the vacancy of index 0 in mid-2003 cannot be deleted. Room 0 in Room 203 separates "Building (2)" from "House Number (3)" (that is, Room 8 on the second floor) and can be deleted. 0 also means that ...

Einstein once said: "I always think it is absurd to explore the meaning and purpose of a person or all living things." I want to study all the numbers of "existence", so it is better to know the numbers of "non-existence" first, so as not to become what Einstein said was "absurd". As a middle school student, my ability is limited after all, and my understanding of 0 is not thorough enough, including the future.

Poor writing, please forgive me!