Summary of Mathematics Knowledge Points in Volume II of Grade One of Beijing Normal University Edition
Addition and subtraction of rational number 1.3
Rational number addition rule:
1. Add two numbers with the same sign, take the same sign, and then add the absolute values.
2. Add two different symbols with different absolute values, take the symbol of the addend with larger absolute value, and subtract the one with smaller absolute value from the one with larger absolute value. Two opposite numbers add up to 0.
When a number is added with 0, it still gets this number.
Rule of rational number subtraction: subtracting a number is equal to adding the reciprocal of this number.
Multiplication and division of rational number 1.4
Rational number multiplication rule: two numbers are multiplied, the same sign is positive, the different sign is negative, and the absolute value is multiplied. Any number multiplied by 0 is 0.
Two numbers whose product is 1 are reciprocal.
Rational number division rule: dividing by a number that is not equal to 0 is equal to multiplying the reciprocal of this number.
Divide two numbers, the same sign is positive, the different sign is negative, and divide by the absolute value. Divide 0 by any number that is not equal to 0 to get 0. mì
The operation of finding the product of n identical factors is called power, and the result of power is called power. In the n power of a, a is called radix and n is called exponent.
The odd power of a negative number is negative and the even power of a negative number is positive. Any power of a positive number is a positive number, and any power of 0 is 0.
Scientific counting method is used to express numbers greater than 10 as the n power of a× 10.
From the first non-zero digit to the last digit on the left of a number, all digits are valid digits of this number.
Knowledge points in the first volume of junior high school mathematics
Parallel lines
1. In the same plane, if two straight lines have no intersection, they are parallel to each other, and it is recorded as: a ∨ b.
2. Parallelism axiom: After passing a point outside a straight line, there is one and only one straight line parallel to this straight line.
3. If two straight lines are parallel to the third straight line, then the two straight lines are also parallel to each other.
4, determine the method of two straight lines parallel:
(1) Two straight lines are cut by the third straight line. If congruent angles are equal, two straight lines are parallel. To put it simply: the same angle is equal and two straight lines are parallel.
(2) Two straight lines are cut by a third straight line. If the internal dislocation angles are equal, two straight lines are parallel. To put it simply: the internal dislocation angles are equal and the two straight lines are parallel.
(3) Two straight lines are cut by a third straight line. If they are complementary to each other, the two straight lines are parallel. To put it simply: the internal angles on the same side are complementary and the two straight lines are parallel.
Properties of parallel lines
(1) Two parallel lines are cut by a third straight line and have the same angle. To put it simply: two straight lines are parallel and have the same angle.
(2) Two parallel lines are cut by a third line, and the internal dislocation angles are equal. To put it simply: two straight lines are parallel and their internal angles are equal.
(3) The two parallel lines are cut by the third straight line and complement each other. Simply put, two straight lines are parallel and complementary.
Sorting out and summarizing the knowledge points of seventh grade mathematics
mirror symmetry
1. When an object is placed in front of a mirror, the mirror will change its left and right direction;
2. When placed perpendicular to the mirror, the mirror will change its up-and-down direction;
3. If it is an axisymmetric figure, when the symmetry axis is parallel to the mirror, the image in the mirror is the same as the original figure;
Through discussion, students may find the following ways to solve the problem of mutual transformation between objects and images:
(1) Take photos with a mirror (pay attention to the placement of the mirror); (2) Using the axial symmetry property;
(3) Numbers can be reversed left and right, and simple axisymmetric figures can also be made;
(4) You can see the back of the image; (5) Imagine in your mind according to the previous conclusion.
Seventh-grade mathematics knowledge points finishing related articles;
★ Summarize the knowledge points of seventh grade mathematics in junior high school.
★ The encyclopedia of mathematics knowledge points in grade seven.
★ Induction of knowledge points in the first volume of junior high school mathematics.
★ Summary of mathematical knowledge points in the first volume of the first day of junior high school.
★ Induction and learning methods of mathematics knowledge points in senior one.
★ Summary of knowledge points of the first-year mathematics people's education edition
★ Summary of seventh grade mathematics knowledge points
★ Summary of knowledge points in junior high school mathematics textbooks
★ Summary of knowledge points in the first volume of seventh grade mathematics
★ Arrangement of Mathematics Knowledge Points in Senior One.