Centimeter is a commonly used unit of measurement in daily life, millimeter is used for measurement with high precision, decimeter is suitable for measurement with large size, and meter is the most commonly used unit of length for measuring large-scale objects. These units have their own applications in different scenes, and understanding their differences and uses can help us better measure and understand the concept of length.

1 cm

A centimeter is a unit of length, equal to one hundredth of a meter. It is often used to measure the length of small objects daily.

2. mm

Millimeter is a unit of length, equal to one thousandth of a centimeter. Often used for more accurate measurement, such as the size of mechanical parts.

3, decimeter (dm)

A decimeter is a unit of length, equal to one tenth of a meter. It is usually used to measure larger dimensions, such as the length of a room or the side length of a cuboid.

4. meter (meter)

Meter is a unit of length, ten times as long as decimeter, and is the most commonly used unit of length, which is used to measure a wide range of objects.

Brief introduction of length unit

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

To understand the unit of length, we must first understand its superordinate concept-unit. The definition of "unit" in Modern Chinese Dictionary is: the name of the standard quantity to measure things. In measurement, a certain kind of quantity is taken as a reference quantity to determine how many times the known quantity is equivalent to the reference quantity, which is called a unit.

For example, centimeter is the unit for measuring length, gram is the unit for measuring mass, and second is the unit for measuring time. As an example of mathematics, it can also be said that 1 is the unit of natural number, and the fraction with the numerator of 1 is the unit of fraction.

When measuring the length of a line segment, you need to select a line segment as the measurement standard and specify its length as 1, which is called the length unit. There are many units in length, the main unit is meter, and the rest are derived units.

When measuring, choose the appropriate length unit according to the actual needs. For example, the length of the runway is in meters, the distance between two cities is in kilometers, and the distance of long jump is in centimeters.