There is never a shortcut to learning. Every subject has its own learning method, but it is always inseparable. As one of the main courses, mathematics, like Chinese and English, needs to be memorized, recited and practiced. Here are some fourth-grade math knowledge points I have compiled for you, hoping to help you.

Knowledge points of mathematics "hectares and square kilometers" in the first volume of the fourth grade of People's Education Edition

1. The area units that have been learned are square centimeter (cm2), square decimeter (dm2), square meter (m2), hectare and square kilometer (km2).

2.( 1) A square with a side length of 1cm and an area of 1cm.

(2) A square with a side length of 1 decimeter and an area of 1 square decimeter.

(3) A square with a side length of 1m and an area of 1m2.

(4) Square with side length 100 m and area 1 hectare. 1 ha = 1 10,000 m2

The area of land can be measured in hectares.

For example, the Bird's Nest covers an area of about 1 hectare. The area surrounded by the runway 400 is about 1 hectare.

(5) A square with a side length of 1000m and an area of 1 km2.

1 km2 = 100 hectares =1100 million m2.

China has a land area of about 9.6 million square kilometers.

3. Conversion between area units:

(1) First, remember the progress between them:

1 km2 = 100 hectares =1100 million m2.

1 ha = 1 10,000 m2

1 m2 = 100 square decimeter

1 square decimeter = 100 square centimeter

1 m2 = 10000 cm2

(2) conversion method:

○ 1 To convert a high-level unit into a low-level unit, it is necessary to use multiplication to calculate, just multiply the number in front of the high-level unit by the ratio between the two units. (that is, the height, the rate of progress, the decimal point moves to the right, and you can see the rate of progress by moving a few places. )

2 To aggregate low-level units into high-level units, it is necessary to calculate by division, as long as the number in front of the low-level unit is divided by the ratio between two units. (that is, reduce the level, divide by the forward speed, move the decimal point to the left, move a few positions, and see the forward speed. )

A. To convert hectares into square meters, just write four zeros directly after the data in front of hectares.

B, to convert square meters into hectares, just remove four zeros from the data in front of the square meters.

C. To convert a square kilometer into a hectare, just write two zeros directly after the data in front of the square kilometer.

D, convert a square kilometer into a square meter, just add six zeros directly after the data in front of the square kilometer.

E, to convert a square meter into a square kilometer, just remove six zeros from the data in front of the square meter.

4, fill in the legal provisions of the area unit:

(1) Land area, province (including municipality directly under the central government) area, provincial capital city area, state (city) area, county, township area, village committee and village area, generally taking "square kilometers" as the unit.

(2) Parks, colleges (schools), stadiums (gymnasiums), etc. , generally in "hectares" as the unit.

(3) Housing (building) area, classroom area, campus greening area, etc. , are generally measured in square meters.

Knowledge points of Understanding Large Numbers, the first volume of fourth-grade mathematics published by People's Education Press.

1.1010,000 is 100,000,1010,000 is 1 million,101 million is 10 million,1010 million is 100 million.

The advance rate between every two adjacent counting units is "10". This counting method is called decimal counting method.

Special attention: the difference between counting units and numbers.

2. When using numbers to represent numbers, these counting units should be arranged in a certain order, and their positions are called numbers.

3. Number of digits: A number contains several digits, that is, several digits. For example, 652 100 is a six-digit number.

According to our country's counting habit, every four digits are counted from the right.

5. How to pronounce hundreds of millions or more:

(1) Grading first, starting from high reading. Read level 100 million, then level 10,000, and finally level 1.

(2) Billions should be read according to the pronunciation of billions, and then the word "billion" should be added at the end. Ten thousand series should be read according to the reading method of ten thousand series, and then the word "ten thousand" should be added after it.

No matter how many zeros there are at the end of each level, don't read them. Other numbers have a "0" or several "0" in succession, all of which are read only.

6, hundreds of millions of words:

(1) Write from bits, first write 100 million levels, then write 10,000 levels, and finally write one level.

(2) If there is no unit, just write 0 on the number.

7, compare the size of the quantity:

The two numbers are different, the one with more numbers is bigger and the one with fewer numbers is smaller.

(2) Two numbers with the same number of digits, starting from the number of digits, the number with the largest number of digits is larger. If the numbers on the numbers are the same, compare the numbers on the next number until the size is compared.

8. Number of rewrites:

Rewrite it into a number in the unit of "10000" or "10000000". Draw a grading line first, divide the integer 10 thousand or integer 100 thousand into four levels, then omit four zeros from each level and replace them with the word "100 thousand"

9. Find out the approximate figures:

The mantissa after omitting ten thousand digits depends on the number on one thousand digits; The mantissa after omitting 1 100 million bits depends on the number on1100 million bits.

When calculating the divisor by "rounding", it depends on whether the number of the omitted mantissa part is less than 5 or equal to or greater than 5. If it is less than 5, the mantissa is discarded and rewritten as a corresponding number of zeros; If it is equal to or greater than 5, advance 1, then discard the mantissa and rewrite it as a corresponding number of zeros.

10, indicating the number of objects: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, ... are all natural numbers. There is no object, which is represented by 0, and 0 is also a natural number. All natural numbers are integers.

1 1, the smallest natural number is 0, there is no natural number, and the number of natural numbers is infinite.

12, calculator ON/CE: switch the clear screen key to clear the contents on the display screen.

AC: Clear the key, clear everything.

DEL: Clear the wrong number or operation symbol just entered.

13. On the abacus, 1 upper bead stands for 5, 1 lower bead stands for 1.

Learning methods of Olympic mathematics in the fourth grade of primary school

One: Take notes

This method is actually very common and simple, but it is difficult for many students to do it. Taking notes has many advantages. First, you can record the essence of the teacher for review. Second, it can train students' writing ability. Thirdly, it can help students develop their learning ability in listening and writing, which is very effective in improving learning efficiency.

Two: wrong title book

Many children are sloppy, but some sloppy are actually caused by students' unclear understanding of knowledge points. Such a topic must be recorded. There are also traps deliberately designed by questioners, which can also be recorded and reviewed regularly. After a long time, many carelessness will naturally be avoided.

Three: study group

Sharing good test questions, methods, skills and experiences with group members on a regular basis can not only increase the affection between classmates, but also learn new things in the process of making friends, improve learning efficiency, cultivate cooperation spirit and enhance coordination ability.

Four: Subject Classification Book

I like the wrong problem book and record the problems I have done. Classification refers to dividing the problems I have done into several categories, one of which is extremely simple and can be read by myself. One kind is difficult, which requires thinking to find a breakthrough, and the other kind is difficult, which requires a lot of comprehensive knowledge and reasoning to solve. The latter two should be the focus of our records. In the process of classifying the test questions, students naturally enhance their further understanding of the test questions.

Five: New solutions to old problems

Look through the original questions from time to time, but the key point is to think about whether there are new ideas and skills for solving problems. This increasing thinking is conducive to the formation of students' thinking habits, as well as the formation of students' divergent thinking, examining ideas from multiple angles and using new knowledge to solve problems at any time.

Summarize the knowledge points of the fourth-grade mathematics related articles in People's Education Press;

★ Summarize the knowledge points of the first volume of mathematics in the fourth grade of primary school.

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

★ Summary of Mathematics Knowledge Points in Grade Four

★ Summary of knowledge points in the first volume of fourth grade mathematics

★ Summarize the knowledge points of fourth grade mathematics.

★ People's Education Edition fourth-grade mathematics knowledge points

★ Summarize the knowledge points of fourth grade mathematics.

★ Summarize the knowledge points of fourth grade mathematics.

★ Summary of Mathematics Knowledge Points in Grade Four

★ Knowledge points in the first volume of fourth grade mathematics