The second grade mathematics first volume knowledge point department edition

It is not difficult to master all the knowledge and knowledge in the world. As long as you study persistently, try to master the rules and reach familiar situations, you can master and use them freely. Learning requires perseverance. Here are some second-grade math knowledge points I have compiled for you, hoping to help you.

Summary of knowledge points in the first volume of the second day of junior high school

1. unit of length: refers to the basic unit for measuring spatial distance, and is the basic unit formulated by human beings to standardize the length. Its international unit is "meter" (symbol "m"), and commonly used units are millimeter (mm), centimeter (cm), decimeter (dm), kilometer (km) and so on. Length units play an important role in various fields.

2. meter: in the international system of units, the standard unit of length is "meter", which is represented by the symbol "m".

3. decimeter: dm is one of the metric units of length, and 1 decimeter is equivalent to one tenth of 1 meter.

4. centimeter: centimeter, length unit. The abbreviation (symbol) is cm.

Unit conversion of centimeters:1cm =10 mm = 0.1decimeter =0.0 1 m =0.0000 1 km.

5.MM: English abbreviation mm (or mm, ㎜)

Clearance at the entrance:1mm = 0.1cm;

6. Carry: In addition, when each digit is equal to the radix, move forward by one digit.

For example, if the number of digits reaches 10, the number will move forward by 1 to become a ten.

In the decimal algorithm, if every digit is full ten, add1to the decimal digit; When there are ten people to ten, add one to a hundred.

7. subtraction without abdication: subtraction without high position. For example: 56-22=34. You can subtract 2 from 6, so you don't have to borrow the first 5.

8. abdication subtraction: the subtraction operation that must borrow from the high position. For example: 5 1-22=39.

1 cannot be reduced by 2, but must be borrowed from Gao 5.

9. Continuous addition: The continuous addition of multiple numbers is called continuous addition. For example: 28+24+23=85.

10. Continuous subtraction: The continuous subtraction of multiple numbers is called continuous subtraction. For example: 85-40-26= 19.

1 1. addition and subtraction: there are both addition and subtraction operations in the operation. For example: 67-25+28=70.

12. Angle: A graph composed of two non-coincident rays with a common endpoint is called an angle. This common endpoint is called the vertex of the angle, and these two rays are called the two sides of the angle.

Symbol: VII

A complete set of formulas for second-grade mathematics knowledge points

1, the perimeter of the rectangle = (length+width) ×2C=(a+b)×2.

2. The circumference of a square = side length ×4C=4a.

3. Area of rectangle = length× width S=ab

4. Area of a square = side length × side length S = a ... a = a.

5. Area of triangle = base × height ÷2S=ah÷2.

6. parallelogram area = bottom x height S=ah

7. trapezoidal area = (upper bottom+lower bottom) × height ÷2S=(a+b)h÷2.

8. Diameter = Radius× 2D = 2r Radius = Diameter ÷2r=d÷2

9. The circumference of a circle = π× diameter = π× radius× 2c = π d = 2π r.

10, circular area = pi × radius× radius? =πr

1 1, the surface area of a cuboid = (length× width+length× height+width× height) × 2.

12, cuboid volume = length× width× height V=abh.

13, the surface area of the cube = side length × side length× 6s = 6a.

14, volume of cube = side length × side length × side length v = a.a.a = a.

15, lateral area of cylinder = circumference of bottom circle × height S=ch.

16, surface area of cylinder = upper and lower bottom area+side area.

s = 2πr+2πRH = 2π(d÷2)+2π(d÷2)h = 2π(c÷2÷π)+Ch

17, cylinder volume = bottom area × height V=Sh

V=πrh=π(d÷2)h=π(C÷2÷π)h

18, volume of cone = bottom area × height ÷3.

v = sh÷3 =πRH÷3 =π(d÷2)h÷3 =π(c÷2÷π)h÷3

19, cuboid (cube, cylinder)

1, number of copies × number of copies = total number of copies/number of copies = total number of copies/number of copies = number of copies.

2. 1 multiple× multiple = multiple1multiple = multiple/multiple = 1 multiple

3. Speed × time = distance/speed = time/distance/time = speed

4. Unit price × quantity = total price ÷ unit price = total quantity ÷ quantity = unit price

5. Work efficiency × working hours = total workload ÷ work efficiency = working hours ÷ total workload ÷ working hours = work efficiency.

6. Appendix+Appendix = sum-one addend = another addend

7. Minus-Minus = Minus-Minus = Minus+Minus = Minus

8. Factor × factor = product ÷ one factor = another factor.

9. Dividend = quotient dividend = divisor quotient × divisor = dividend

Summary of Mathematics Checking Calculation Method in Senior Two

1. Let the students "feel at ease": One or two minutes before class, the students' hearts are still in the excited state of playing between classes. It is necessary for students to adjust themselves during this time and calm down before class in order to concentrate. Teachers in all subjects can cooperate well to cultivate students' habit of preparing school supplies for the next class before going to activities. At the beginning of the class, when the students were very excited, the teacher said that shouting had no effect. You can clap your hands rhythmically, and the students clap three times together and then sit down.

2. Make students "alert": To be "alert", you must listen and remember. Therefore, the key content of each class allows students to repeat the teacher's speech or the students' speech, and can also do some listening and calculation exercises frequently to cultivate students' listening attention.

3. Let students "know": If you want to make it back, you have to understand that students just listen and don't think about it, which means they don't listen. In class, we should pay attention to guiding students to talk about their own views and ideas after listening to other people's speeches, and find out where others' speeches are good, wrong or need to be supplemented.

4. Create a lively and relaxed listening atmosphere under the premise of ensuring classroom discipline: the new curriculum does not advocate the very rigid teaching form in the past. As long as students can concentrate on their studies, teachers don't have to be strict about whether students are sitting correctly. In class, they can take some forms of deskmate communication and group cooperation, operate or discuss in cooperation and interact with teachers and students. Of course, in cooperation, teachers should pay attention to the role distribution and assign each team member a post, so everyone has something to do. Before cooperation, teachers should make clear the requirements of cooperation, which will certainly stimulate students' sense of responsibility and participation, and avoid group cooperation becoming a mere formality. In this way, students' thinking is stimulated and they will be more willing to listen under the guidance of teachers.

Related articles compiled by the knowledge point department of the first volume of the second grade mathematics;

★ Second grade version of mathematics knowledge points

★ Summary of second-grade mathematics knowledge points

★ Knowledge points of second-grade mathematics teaching

★ Guidance of mathematics learning methods in the second grade of primary school

★ Best learning method recommendation

★ The first edition of the fifth grade mathematics knowledge department

★ Guidance on learning methods in the second grade of primary school

★ Learning skills of primary school students