Why 0 is a natural number. Historically, mathematical circles at home and abroad have considered 0 as a natural number: 0 as a natural number and 0 as a natural number. After the founding of People's Republic of China (PRC), the natural numbers of textbooks in China include 0. Objectively, foreign mathematical norm 0 is a natural number. In order to facilitate international communication, Chinese national standard (gb3 100-3 102-93) and measurement unit (1 1-2.9) were promulgated on 1993. In recent years, the textbooks for learning mathematics have been revised according to the national standards. That is, the object, 0 means. 0 is a natural number. Thinking: Is the most number "1" or "0"? 0 is the most natural number. Is it "1" or "0" with the most digits? 0 is clearly classified as a natural number, and the most significant digit is 1. Yao, the natural number is 0 now, and the most digits are 1? Is xu teacher's suspicion. I think the most number is 1. Therefore, 0 represents an object, and notation is a symbol indicating vacancy. For example, 3005 "0" means a number, a hundred numbers or a vacancy. Although the second adjustment classified "0" as a natural number, the concepts of several numbers did not change. "Several numbers" means that "a number represented by a significant number is called a number, a significant number, and a number represented by a significant number on the left is called a number ..." Assuming that a number is 0, which number is 10 or 00? What's the minimum number of digits, four digits ... or less? "Eight Books for Nine-year Compulsory Education and Six-year Mathematics Teachers" wrote on page 98: "Usually, natural numbers, including numbers with several numbers, are called numbers. For example, 2, a number with numbers, is called digits；; 30 numbers with numbers are called numbers; 405 numbers with numbers are called numbers ... but note: 0 is several numbers. Refers to the largest number of digits, the largest number of digits, usually in the range of non-zero natural numbers. , the maximum number of digits is 9 and the maximum number of digits is1; The maximum number of digits is 99 and the maximum number of digits is10; The maximum number of digits is 999, and the maximum number of digits is100 ... "In conclusion, although" 0 "is the most natural number, it is still called" digits "and even more called the maximum number. Thinking: Is the unit for calculating natural numbers "1"? As we all know, 0 is the most natural number. 0 plus 1 1, 1 plus 12, 2 plus 13, ... continues to be any natural number. The arrangement order of natural numbers is known, and the surface natural number is 1. So any natural number is a combination of a number 1, and 1 is the unit of natural numbers. 0 is a natural number set by 0 1 Thinking 4: Is 0 a multiple of other nonzero natural numbers? The meanings of "divisible number" and "multiple of divisor" in the book "Nine-year Compulsory Education and Six-year Mathematics" have not changed. The 54-page textbook says, "Because 0 is divisible by 2, 0 is an even number". By analogy, 0 can be divisible by a non-zero natural number. According to the meaning of divisor multiple, 0 is a multiple of any non-zero natural number, and any non-zero natural number is a divisor of 0. But consider studying prime factors, the most common divisor and the most common multiple, which are generally in the range of non-zero natural numbers, such as the most common multiple, and are excluded from 0. Here, the book Nine-year Compulsory Education and Six-year Mathematics clearly points out on page 50: "In order to facilitate learning multiples of approximate numbers, some numbers generally include 0". Avoid some necessary troubles. However, some laws must be corrected. For example, the conclusion that "the greatest multiple of a natural number is its self-body" and "the divisor of a natural number is limited" must be corrected. Thinking 5: Is 0 a composite number? Teaching, the group of natural numbers, the situation: it is the odd and even set of natural numbers; Yes, the sum of prime numbers and 1 set of natural numbers. Now the members of the set of 0 natural numbers are asked by the teacher: Is 0 a composite number? It has been said that "the study of multiples of divisors generally includes 0", but academic research and discussion have never been done. Author, 0 has countless divisors. According to the meaning of approximate number in the book "Nine-year Compulsory Education and Six-year Mathematics", "A number is called a composite number if it is divided by other divisors of 1." It seems that 0 should belong to the range of composite numbers, but if you think about it carefully, 0 is a special natural number, because the "body" divisor of non-zero natural numbers, such as 1 is the divisor of 1, 2 is the divisor of 2 ..., and the natural number of 0 is just smaller than the "body" divisor, so it is reduced to a composite number. Imagine: suppose 0 is a composite number, is it expressed by multiplying prime factors? The contradiction of "how many prime numbers are multiplied by each composite number" is classified as "prime number, composite number". Of course, it needs the approval of experts from authoritative organizations. However, it is obvious that 0 is a composite number and an avoidance. Thinking 6: "Any adjacent natural number is a prime number"? 0 is a natural number, and the conclusion is undoubtedly correct. Since 0 is a natural number, we only study whether the natural number adjacent to "0 1" is a prime number. According to the book Mathematics of Nine-year Compulsory Education and Six-year System, the meaning of prime number is: "The common divisor is only 1, which is called prime number." The author thinks that 0 has countless divisors, and the divisor of 1 is its body. To sum up, the common divisor of 0 1 is only "1", so 0 1 is a prime number. Naturally, the conclusion that any adjacent natural number is a prime number is correct.

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