1, millimeter (mm): millimeter is a smaller unit of length, and is usually used to measure smaller items, such as pencil lead and screws.
2. centimeter (cm): centimeter is one of the commonly used units of length, which is usually used to measure shorter objects, such as stationery and books.
3. Decimeter (dm): Decimeter is a unit of length greater than cm, which is usually used to measure long objects, such as tables and walls.
4. Meter (m): Meter is one of the commonly used units of length, which is usually used to measure long objects, such as playgrounds and rivers.
5. Kilometers (km): Kilometers are longer units of length than meters, and are usually used to measure longer distances, such as the distance between cities and countries.
The conversion relationship between length units is as follows:
1 m is equal to 10 decimeter, 1 decimeter is equal to 10 cm, 1 cm is equal to 10 mm, 1 km is equal to 1000 m, learning.
The second-year students also need to know some concepts related to length units, such as measuring tools, measuring methods, unit conversion and so on. For example, using ruler, tape measure and other tools to measure, mastering the correct measurement method and reading method, can carry out simple unit conversion.
In the study of length units, students need to deepen their understanding and knowledge of length units through practical operation and inquiry activities. For example, through actual measurement, comparing the length of objects, or through inquiry activities, we can understand the applicable scope and conversion relationship of different length units.
In the study of length units, students also need to pay attention to some common mistakes and traps. For example, when converting units, it is easy to ignore the advancing rate between different units, resulting in wrong results. In addition, when measuring with measuring tools, we need to pay attention to the correct reading method and measuring method to avoid mistakes and mistakes.