What are the key knowledge of Grade 7 Mathematics, English, and Chinese?

1. Positive and negative numbers. 1. Positive number: the number greater than 0.

2. Negative number: the number less than 0.

3. The positive number is greater than 0, the negative number is less than 0, and the positive number is greater than the negative number.

Note: 0 is neither positive nor negative; -a is not necessarily a negative number, and +a is not necessarily a positive number such as silver celery; p is not a rational number;

2. Rational numbers.

1. Rational number: a number composed of integers and fractions. Includes:

Positive integers, 0, negative integers, positive fractions, negative fractions. It can be written in the form of a ratio of two integers. (An irrational number is a form that cannot be written as a ratio of two integers, it is written as a decimal, and the number after the decimal point is infinitely non-cyclical.)

Such as: 3. Number axis. 1. Number axis: The number is represented by the points on the straight line, and this straight line is called the number axis.

Draw a straight line, take any point on the line to represent the number 0, this zero point is called the origin, and it is stipulated that the straight line is positive from the origin to the right or up; Select the appropriate length as a unit length to take a point on the number line. ）

2. The three elements of the number axis: origin, positive direction, and unit length.

3. Opposite numbers: Only two numbers with different symbols are called opposite numbers. The opposite of 0 is still 0.

The sum of the inverse numbers of the width of the fight is 0 a+b=0 a, and b is the opposite of each other.

The 7th grade math knowledge points are as follows:1. Mathematics stipulates that rational numbers are represented on the number line, and their order from left to right is the order from small to large, that is, the number on the left is smaller than the number on the right.

2. A straight line with an origin, positive direction, and unit length is called the number axis.

3. Addition commutative law: two numbers are added, the position of the added number is exchanged, and the sum is unchanged.

4. Multiply numbers with numbers, and still use " "multiply, don't use" · Multiplication, nor can the multiplication sign be omitted.

5. The difference between A and B is written as A-B, pay attention to the alphabetical order; If only the difference between the two numbers is said, when the two numbers are set to a and b respectively, they should be classified and written as a-b and b-a.

Grade 7 math knowledge points are:1. Inequality.

1. The formula that uses a less than sign or greater than a sign to express the size relationship is called an inequality.

2. The value of the unknown that makes the inequality true is called the solution of the inequality.

3. The range of values of x that can make the inequality valid is called the set of solutions of the inequality, referred to as the solution set.

4. There is an unknown, and the number of unknowns is an inequality of 1, which is called a one-dimensional inequality.

Second, the square root.

1. If the square of the lead finger of a positive number x is equal to a, then this positive number x is called the arithmetic square root of a, and 2 is the root exponent.

2. The arithmetic square root of a is read as "root number a", and a is called the number of squares to be opened.

3. The arithmetic square root of the wax bond 0 is 0.

4. If the square of a number is equal to a, then this number is called the square root or quadratic root of a.

5. The operation of finding the square root of a number a is called open square.

3. Cube root.

1. If the cube of a number is equal to a, then the number is called the cube root or cubic root of a.

2. The operation of finding the cube root of a number is called opening square.

Fourth, the perpendicular line. 1. When two straight lines intersect, and one of the four corners is a right angle, then the two straight lines are perpendicular to each other. One of the straight lines is called the perpendicular line of the other straight acacia wiring, and their intersection is called the vertical foot.

2. Lead the perpendicular line from the point outside the straight line to the straight line, and the line segment between this point and the vertical foot is called the perpendicular line segment.

3. The perpendicular segment is a part of the perpendicular line, which is a line segment, one end is a point, and the other end is a perpendicular foot.

1. Adjacent complement angle: Among the four corners formed by the intersection of two straight lines, the two corners with a common vertex and a common edge are adjacent complement angles.

2. Opposite top angles: The two sides of one corner are the opposite extension lines of the other called two sides, and the two corners like this are opposite to each other.

3. Perpendicular line: When two straight lines intersect at right angles, they are called perpendicular to each other, and one of them is called the perpendicular line of the other.

4. Parallel lines: In the same plane, two straight lines that do not intersect are called parallel lines.

5. Wild Bu isotope angle, internal wrong angle, and same side inner angle:

Isotopic angle: A pair of angles with the same positional relationship like 1 and 5 like this is called an isotopic angle.

Misalignment: 2 and 6 A pair of angles like this is called an internal misalignment.

Ipsilateral Inner Angle: A pair of angles like 2 and 5 like this is called the ipsilateral inner angle.