Positive integer:
Used to represent the number of objects? 1, 2, 3, 4, 5 ... are called positive integers. What is the difference between two adjacent positive integers? 1。
0: 0? Are numbers, natural numbers and integers, but not positive or negative integers.
0? It can mean "nothing", or it can be used as the boundary of some quantities, such as? 0℃ and so on.
0? This is an even number. 0? No division, no denominator, no comparison.
Negative integer: Numbers like-1, -2, -3, -4, -5 ... are called negative integers. Is there a phase difference between two adjacent negative integers? 1。
Integer: Numbers such as …, -3, -2,-1, 0, 1, 2, 3… are collectively called integers.
Integers include negative integers, 0? And positive integers.
The number of integers is infinite. A natural number is part of an integer.
Natural number: used to represent the number of objects? 0, 1, 2, 3, 4, 5, 6, 7 ... are called natural numbers. Natural numbers include? 0? And positive integers.
Positive number: positive numbers include positive integers, positive fractions, positive decimals, positive percentages, etc.
Negative numbers: negative numbers include negative integers, negative fractions, negative decimals and negative percentages. Negative numbers can represent quantities with opposite meanings.
Number pair: When a number pair is used to represent a position, the first number represents a column and the second number represents a row.
How to read and write numbers:
Readers and authors should go from high to low, at the end of each level? 0? Don't read it. How many numbers are there in a line? 0? Read only one 0. Both reading and writing should be graded. Like what? 534007000602? Reading: 534,007,006,002.
Rating:? It means "unit"? 1 "is divided into several parts on average, and the number representing such a part or parts is called a fraction. The number representing one of them is called a fractional unit. For example:? 7/ 12? What is the decimal unit of? 1/ 12? It has seven such decimal units.
Real score:? Fractions with numerator less than denominator are called true fractions. The real score is less than? 1。
False fraction: Fractions with numerator greater than or equal to denominator are called false fractions. Is the false score greater than or equal to? 1。
With fraction: The number composed of integer (except zero) and true fraction is called with fraction. Taking points is another manifestation of false points, which can be mutually beneficial.
Basic attributes of a score:
The numerator and denominator of a fraction are multiplied or divided by the same number (except zero) at the same time, and the size of the fraction remains the same, which is called the basic property of the fraction.
Decimal: Decimal is a special form of fraction. But you can't say that decimals are fractions.
Cyclic decimal: a decimal, starting from a certain bit of the decimal part, and one or several numbers are repeated in turn. Such decimals are called cyclic decimals.
Pure Cyclic Decimal: The cyclic decimal starting from the first digit of the decimal part is called pure cyclic decimal.
Mixed cycle decimal: the cycle part is not the cycle decimal starting from the first decimal part. It is called mixed cyclic decimal.
Finite decimal: the number of digits in the decimal part of a decimal is limited, and such a decimal is called a finite decimal.
Infinite decimal: The number of digits in the decimal part of a decimal is infinite, and such a decimal is called an infinite decimal. Cyclic decimal is infinite decimal.
Subtraction: subtraction-subtraction = difference. Subtraction is the inverse of addition.
Multiplication: The simple operation of finding the sum of several identical addends is called multiplication. Factor × factor = product
Division: dividend = quotient. Division is the inverse of multiplication.
The arithmetic of addition and subtraction;
Additive commutative law: A+B = B+A.
Additive associative law: a+b+c = a+(b+c)
The arithmetic of subtraction: A-B? -c=a-(b+c)
Law of multiplication and division:
Multiplicative commutative law: ab = ba
Law of multiplicative association: ABC = a (BC)
Multiplication and distribution law: (a+b) c = AC+BC? Or (a-b) c = AC-BC.
Division algorithm: a ÷ b ÷ c = a ÷ (b× c)
Invariance of quotient: two numbers are divided, and the dividend and divisor are multiplied or divided by the same number (0? Except), the size of the quotient remains unchanged (the size of the remainder changes).
Product invariance: one factor is enlarged several times, and the other factor is reduced by the same multiple, and its product remains unchanged.
The meaning of multiplication:
1. What is the sum of several identical addends? For example: 27× 13, which means seeking? 13? Answer? 27? What's the total? You can still ask for it? 27? what's up 13? What is the multiple?
2. What is the score of a number? For example: 27 × 0.3? Meaning: beg? 27? How much is three tenths?
The meaning of division:
1. Divide a number into several parts. How much is each part? For example, what does 24÷3 mean? 24? Average share? 3? How many copies?
2. How many times is one number than another? For example: 24÷3, indicating? 24? what's up 3? How many times?
3. How many divisors does a number have? Like what? 24÷3? Show? 24? How much is in it? 3。
4. Find the score of a given number. For example: 24÷3? Know a number? 3? What is the era? 24,
Separability and division:
Divisibility: divisor, divisor and quotient are integers (divisor is not? 0)。
Division: Division can be said to be division, but division is not necessarily division. For example, l ÷ 5 = 0.2 is called division, not division, because quotient is a decimal. Another example is:10 ÷ 3 = 3.33 ..., which is neither divisible nor exhaustible, but inexhaustible.
Factors and multiples:
When the number A is divisible by the number B, it is said that the number A is a multiple of the number B and the number B is a factor of the number A ... for example? 12 ÷ 3 = 4, just say? 12? what's up 3? A multiple of 3? what's up 12? The factors. These two concepts are relative, and a natural number does not exist, whether it is a multiple or a factor. For example: "3? Is a factor ",is a mistake. Can only say? 3? what's up 12? The factor, or? The factor of 12 is 3. Another example is: "12? Is a multiple ",which is also a mistake. Can only say? 12? what's up 3? A multiple of, or? 3? What is the multiple of? 12。
Odd and even numbers: what can it be? 2? A divisible number is called an even number and cannot be divisible? 2? Divisible numbers are called odd numbers.
Prime number and composite number: the factor of a number is only? 1? And its two factors are called prime numbers, also called prime numbers, such as 2. The factor of a number except? 1? Besides itself, there are other factors. This number is called composite number, such as? 4。
100? Prime numbers within: 2357L1131719 23 29 3l 37 4l 43 47 53 596167 7173 79 83 89 97.
1? It is neither a prime number nor a composite number. What is the smallest prime number? 2. What is the minimum composite number? 4。
Common factors:
The factors shared by several numbers are called common factors. Its number is limited. There is the biggest one. And the smallest, what is the smallest common factor? 1。
Prime number:
The common factor of two numbers is only? 1 In the absence of other common factors, these two numbers are called prime numbers. Like what? 8? And then what? 9, 1 1? And13,6? And then what? 7。
Any two prime numbers are prime numbers. But the coprime of two numbers is not necessarily a prime number. Like what? 8? And then what? 9? Coprime, but both are complex numbers.
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