# How to explain the units of measurement?

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### How to explain the units of measurement?

**Lengths are usually measured using the unity meter (m), its multiples and its sub-multiples:**

- The kilometer (km) is equal to 1000 meters.
- The hectometre (hm) is equal to 100 meters.
- The decametre (dam) is equal to 10 meters.
- The decimetre (dm) is equal to 0.1 meter.
- The centimeter (cm) is equal to 0.01 meter.

### How to place the units of measurement?

For each number, we will take its digit from **units** and we’re going **to place** in the column that corresponds to the**unit of measure** in which the number is expressed. For example, for a value expressed in L, we will take its figure from **units** and we’re going **to place** in the L column.

### How to place in a unit table?

3:355:57Suggested clip 55 secondsUsing a conversion table (unit of length, mass, capacity)YouTube

### What is measurement?

In the natural sciences, measurement is a method of objective and reproducible comparison of a characteristic of objects. Rather than comparing the objects two by two, we indicate the ratio of each of them to an object defined by a convention called unit of measurement.

### What is physical measurement result?

A complete physical measurement result includes a numerical estimate of the quantity, the designation of the unit of measurement, an expression of the measurement uncertainty and the main test conditions. Uncertainty is an integral part of measurement, and may even be its main result.

### What is the difference between physical measurement and comparison?

Physical measurement aims for objectivity and reproducibility. The comparison is numeric; a well-defined characteristic of the object is expressed by a rational number multiplying unity. A complete physical measurement result includes a numerical estimate of the quantity, the designation of the unit of measurement, …

### How to calculate the measured length?

= 15.5 cm and U(l)= ± 0.3 cm. The measured length will then be expressed as l = (15.5 ± 0.3 cm). k: a coefficient and which depends on n and the level of confidence in the measurement (often 95%).