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 behind 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.
People's education printing plate fourth grade first volume mathematics "hectare and square kilometer" exercise.
1. Fill in the blanks. 1.2 hectares = () square meters
2. 10 km2 = () hectares
3.50000 square meters = () hectares
4.400 hectares = () square kilometers
5. 1 km2 = () m2
6.3 million square meters = () square kilometers
2. Judge whether the following statement is correct.
1. The area of a square with a side length of 1 00m is1hectare ().
2. 1 km2 = 1 10,000 m2. ( )
The area of a classroom is 80 square centimeters. ( )
4.5 hectares = 50,000 square meters. ( )
The relatively large land area is generally measured in square kilometers. ( )
3. multiple choice questions.
1. The propulsion rate between square kilometers and hectares is ().
10 b . 100 c . 1000d . 10000
2. The area of West Lake in Hangzhou is about 600 ()
A. square meters, b square kilometers, c hectares and d square centimeters
A square wheat field is 400 meters long and can harvest 3 tons of wheat per hectare. This square wheat field can harvest () tons of wheat.
48-480 AD
4. 100 The square with a side length of 1000 meters has an area of () hectares.
10 b . 100 c . 1000d . 10000
A playground with a length of 200 meters and a width of 100 meters, if the length and width are doubled, the area will increase by () hectares.
A.2 B.4 C.6 D.8
4. Fill in the appropriate company name in ().
1. Mount Huashan in Xiyue, one of the five mountains in China, covers an area of about 148 ().
2. The school playground covers an area of about 10000 ()
Beijing Olympic Forest Park covers an area of about 680 ().
4. The Bird's Nest covers an area of about 20 ().
5. China's marine area is about 4.7 million ().
Verb (abbreviation of verb) is filled with ">" in (). ,"