1 hectare =10000m2; 1 m2 = 100 square decimeter; 1 square decimeter = 100 square centimeter; 1 cm2 = 100 mm2.

Extended data:

Commonly used area units are hectares, acres, square kilometers, square meters, square centimeters and so on. The conversion mentioned here often refers to the exchange calculation of units between regions. Such as: 1 mu =0.0666666 hectares =666.6666 square meters, etc.

The commonly used conversion formula of land area is 1 mu =60 square abbot =6000 square feet, 1 mu = 666.6 square meters. In fact, there is a more practical formula to calculate the land area:

The square meter is changed to mu, and the formula is "add half to the left and move three". 1 m2 = 0.0015mu, for example, how many mu is128m2? The calculation method is 128 plus half of 128: 128+64= 192, and then move the decimal point three places to the left, that is, the mu number is 0. 192.

Mu is square meters, and the calculation formula is "divide by three, move right by three". If you want to calculate how many square meters 24.6 mu equals, 24.6÷3=8.2, which is 16.4 after doubling, and then move the decimal point to the right by 3 places, the square meter is 16400.

Primary school mathematics is to teach children a series of knowledge about number, four operations, the calculation formula of figure and length, unit conversion and so on through textbooks, which lays a good mathematical foundation for junior high school and daily life calculation. Frieden Noel, a Dutch educator, said: "Mathematics comes from reality and must be rooted in reality and applied to reality."

Indeed, modern mathematics requires us to observe the world from a mathematical perspective and explain the world in mathematical language. Judging from the mathematics learning psychology of primary school students, the learning process of students is not a passive absorption process, but a reconstruction process based on existing knowledge and experience.

Therefore, learning while doing and learning while playing will make children learn more actively. From our educational goal, while imparting knowledge, we should pay more attention to cultivating students' comprehensive ability of observation, analysis and application.