1, no, cm
2. Right
3. no, dear.
4. No, centimeters
5. Right
6.no, dear
analyse
1, the children's desk 1 meter is a little more, and the math textbook cannot exceed one meter, so it is 26 cm.
2. Generally, the length of the lamp tube is similar to that of a desk, so it is 50 cm, that's right.
The width of one index finger is about 1 cm, and the height of the room can't be as high as the width of three index fingers, so the height of the room is 3 meters.
4. A row is about 10 cm, and the thickness of the dictionary will not exceed one meter, so the dictionary cannot be 6 meters thick, but 6 cm.
Trees are relatively tall objects, some of which are shorter than flagpoles and 8 meters high, which is reasonable.
6. 10 cm is about the length of a triangle. The length of a classroom can't be so short, so it should be measured in meters.
Extended knowledge
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 "meter" (symbol "m"), and commonly used units are millimeter (mm), centimeter (cm), decimeter (dm), kilometer (km), meter (m), micron (micron) and nanometer (nm). 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.