What is a natural number in primary school mathematics, and the definition concept of natural number

Natural number. When we count objects, we use them to express the number of objects ,......, 1, 2, 3It's called a natural number. There is not a single object, which is denoted by 0. 0 is also a natural number. Natural numbers are all integers.

Straight line; Straight lines are infinite.

Line Segment: A segment between two points on a line is called a line segment. The line segment has two endpoints. A line segment is a part of a straight line.

Ray: Extend one end of the line segment indefinitely to get a ray. There is only one endpoint for a ray.

Angle: A figure consisting of two rays drawn from a point is called an angle. This point is called the vertex of the corner. These two rays are called the edges of the horns. Horns are usually represented by the symbol " ". As shown below: edges. Vertex.

Side. Compare the size of the corners: first overlap the vertices of the two corners with one edge, and then look at the position of the other edge. Whichever corner has the other side on the outside, the corner is larger. If the other edge also coincides, the two angles are equal.

The size of the angle depends on the size of the two sides, and the larger the fork, the larger the angle. The size of the horn has nothing to do with the length of the drawing on both sides of the horn.

Measurement of Angles: The unit of measurement of angles.

is "degree", which is represented by the symbol "°". Divide the semicircle into 180 equal parts, and the opposite angle of each part is called the angle of 1 degree. Written as 1°, when measuring the angle with a protractor, place the protractor on top of the angle so that the center of the protractor and the vertex of the angle coincide.

The 0° line coincides with one side of the angle, and the scale on the protractor on the other side of the angle is the degree of the angle.

Classification of angles: Angles greater than 0° and less than 90° are called acute angles. An angle equal to 90° is called a right angle. Angles greater than 90° and less than 180° are called obtuse angles.

The two sides of the angle form a straight line, and the angle equal to 180° is called a flat angle. A ray rotates around its endpoint to form a 360° angle called a circumferential angle.

Perpendicular. When two lines intersect at right angles, these two lines are called perpendicular to each other, and one of the straight lines is called the perpendicular line of the other straight line (as shown in Figure 1 below), and the intersection point of these two straight lines is called the perpendicular foot.

Parallel: Two straight lines that never intersect in the same plane are called parallel lines.

as shown in Figure 2 below). It can also be said that these two straight lines are parallel to each other.

Natural numbers are not a strictly mathematical concept and are ambiguous. Usually refers to:"The number that results from counting".Some people or textbooks believe that natural numbers are positive integers, and the current curriculum reform used to stipulate this.

Today's textbooks stipulate that natural numbers include: zero and positive integers.

But positive integers, zero and negative integers, are strictly mathematical concepts without ambiguity.

If you want to say the solution, it can only be: obey the textbook, and the natural number means"Zeros and positive integers".

I hope that those who write textbooks in the future will not stir up confusion. You must know that when people count, they don't start counting from 0. Except that you deliberately start from 0.

To put it simply, it is an integer greater than or equal to 0.

The definition concepts of natural numbers in elementary school mathematics are as follows:

A number used to measure the number of pieces of a thing or to represent the order of things. i.e. digital 0, 1, 2, 3, 4 ,......The number represented. The number that represents the number of objects is called a natural number, and the natural number starts from 0 (including 0), one after the other, forming an infinite collective.

Classification

It is divided by whether it is divisible by 2 or not.

It can be divided into odd and even numbers.

1. Odd number: A number that is not divisible by 2 is called an odd number.

2. Even numbers: Numbers divisible by 2 are called even numbers.

3. Special attention: 0 is an even number. (In 2002, the International Mathematical Association stipulated that zero is an even number, and in 2004, China also stipulated that zero is an even number.) Even numbers can be divisible by 2, and 0 is fine, except that the number is still 0, but it cannot be said that it is not reduced).

Score by the number of factors.

It can be divided into prime numbers, composite numbers, and 1

1. Prime numbers: Natural numbers with only two factors, 1 and itself, are called prime numbers. Prime numbers are also called prime numbers.

2. Composite number: A natural number that has other factors besides 1 and itself is called a composite number.

There is only 1 factor. It is neither prime nor composite. Of course, 0 cannot be calculated as a factor, and it is also a non-prime and non-composite number.

Basic features:

A number used to measure the number of pieces of a thing or to represent the order of things. i.e. digital 0, 1, 2, 3, 4 ,......The number represented. Natural numbers start with 0 and follow each other to form an infinite set.

There are addition and multiplication operations in the set of natural numbers, and the result of adding or multiplying two natural numbers is still a natural number, and it can also be subtracted or divided, but the results of subtraction and division may not be natural numbers, so subtraction and division operations are not always true in the set of natural numbers. Natural numbers are the most basic of all the numbers that people know.

In order to have a strict logical foundation for the number system, mathematicians in the 19th century established two equivalent theories of natural numbers, the ordinal number theory of natural numbers and the cardinal theory, so that the concepts, operations and related properties of natural numbers were strictly discussed.

Natural numbers include:Positive integerand zero. Natural numbers are integers, but integers are not all natural numbers, for example: -1 -2 -3 ......It's an integer, not a natural number.

Natural numbers are infinite.

General Concept of Natural Numbers:

Natural numbers are markers of the common characteristics of all equivalent finite sets. Integers include natural numbers, so natural numbers must be integers, and they must be non-negative integers.

Natural numbers are integers (natural numbers include positive integers and zeros), but integers are not all natural numbers, for example: -1 -2 -3 ......It's an integer, not a natural number. Natural numbers are infinite.

The set of all non-negative integers is called a non-negative integer set.

i.e. the set of natural numbers.

When counting objects, the number that is counted is called a natural number. Natural numbers have two meanings: quantity and order, and are divided into cardinal numbers and ordinal numbers.

Natural number. It refers to the number of pieces used to measure things or the number of things that represent the order of things. i.e. digital 0, 1, 2, 3, 4 ,......The number represented.

Natural numbers start with 0 and follow each other to form an infinite collective. Natural numbers are orderly, infinite. It is divided into even and odd numbers, composite numbers and prime numbers.

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A number used to measure the number of pieces of a thing or to represent the order of things. i.e. digital 0, 1, 2, 3, 4 ,......The number represented. The number that represents the number of objects is called a natural number, and the natural number starts from 0 and follows one after the other to form an infinite collective.

It can be divided into odd and even numbers.

1. Odd number: A number that is not divisible by 2 is called an odd number.

2. Even numbers: Numbers divisible by 2 are called even numbers. That is, except for odd numbers, they are even numbers.

Note: 0 is an even number. (In 2002, the International Mathematical Association stipulated that zero is an even number.) In 2004, zero was also an even number. Even numbers are divisible by 2, and 0 is fine, but the number is still 0).

It can be divided into prime numbers, composite numbers, 1 and 0.

1. Prime number: A natural number with only two factors, 1 and itself, is called a prime number. Also known as prime numbers.

2. Composite number: A natural number that has other factors besides 1 and itself is called a composite number.

There is only 1 factor. It is neither prime nor composite.

4. Of course, 0 cannot be calculated as a factor, and like 1, it is neither a prime number nor a composite number.

All matter in this world is made up of molecules, which is equivalent to being made up of numbers. We all learned to count in elementary school math textbooksNatural numbers are simply numbers that represent the number of objects, which includes , etc., isAn infinitely looping non-negative integer starting at zero。Integers include natural numbers, so natural numbers are a part of integers.

Because natural numbers represent the number of objects, all we can see are integers from zero to infinity, and fractions are invisible to the naked eye. Natural numbers have two properties, one is orderedness and the other is infinity. <>

Natural number alsoThese include odd, even, prime, and composite numbers。We are all familiar with odd numbers, which are similar to 13579, of course, zero is an even number and it is also a natural number. If you want to learn science in the future, it is important to learn mathematics well.

At the beginning, we need to start with these concepts and consolidate the most basic knowledge. Mathematics in primary school does not require too much numeracy ability, it tests our basic knowledge, and only by remembering these basic knowledge points can we continue to learn mathematics in the future. If you have a question about who is the smallest natural number, then the answer must be zero.

Because natural numbers are part of integers and are non-negative, so do weIt can be called a non-negative integer

In fact, it comes down to the fact that in the first place, we don't think of zero as the smallest natural number. In 2002, our country set zero as the smallest natural number, because it was France that first regarded zero as a natural number, and later for various reasons, our country also changed the primary school textbook to treat zero as the smallest natural number. The above is what I think of the concept of natural numbers, I hope everyone can understand, today's children's learning is the most important, don't be delayed by the Internet in the future, you are all the pillars of the future motherland, come on to win glory for the motherland.

Natural number: The concept of natural number refers to the number of sharp cracks used to measure things or to express the number of things in parts. i.e. digital 0, 1, 2, 3, 4 ,......The number represented. Natural numbers start from 0 and follow each other to form an infinite collective.

A natural number is just an integer that is not less than 0 (that is, 0 and a positive integer), so there are an infinite number of natural numbers, which are usually represented by n. The number of natural numbers is unlimited.

Ordinal number theory is the work of the Italian mathematician GPiano brought it up. He summarized the properties of natural numbers and gave the following definition of natural numbers in axiomatic terms:

The set of natural numbers n is the set of the following conditions: n has an element in it, denoted as 1. Each element in n can find an element in n as its successor.

1 is not the successor of any element. Different elements have different successors. (Inductive axioms) any subset of n m, if 1 m, and as long as x is in m it can be deduced that x's successor is also in m, then m = n.

Natural number, i.e. ......

Formula: Number sequence 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, ,......n, which is called a natural sequence.

The formula for the passage of a natural sequence of numbers is an=n.

The first n terms of the natural series and sn=n(n+1) 2. sn=na1+n(n-1)/2

The essence of the natural sequence is that it is an equal difference series, with the first term a1=1 and the tolerance d=1.