Units of measure are models established to measure different quantities, such as length, capacity, mass, time and volume.
The International System of Units (SI) defines the default unit for each quantity. Based on the decimal metric system, the SI arose from the need to standardize the units that are used in most countries.
Length Measurements
There are several length measurements, such as yard, inch and foot.
In SI the standard unit of length is the meter (m). It is currently defined as the length of the distance traveled by light in a vacuum during a time interval of 1/299,792,458 of a second.
The multiples and sub-multiples of the meter are: kilometer (km), hectometer (hm), decameter (dam), decimeter (dm), centimeter (cm) and millimeter (mm).
Capacity Measures
The most used unit of measure for capacity is the liter (l). The gallon, the barrel, the quart, among others are also used.
The multiples and submultiples of the liter are: kiloliter (kl), hectoliter (hl), dekaliter (dal), deciliter (dl), centiliter (cl), milliliter (ml).
Mass Measures
In the International System of Units the measure of mass is the kilogram (kg). A platinum and iridium cylinder is used as the universal kilogram standard.
The mass units are: kilogram (kg), hectogram (hg), decagram (dag), gram (g), decigram (dg), centigram (cg) and milligram (mg).
The arroba, pound, ounce and tonne are also examples of mass measurements. 1 ton is equivalent to 1000 kg.
Volume Measurements
In SI the volume unit is the cubic meter (m3). The multiples and submultiples of the m3 are: cubic kilometer (km3), cubic hectometer (hm3), cubic decameter (dam3), cubic decimeter (dm3), cubic centimeter (cm3) and cubic millimeter (mm3).
We can transform a measure of capacity into volume, as liquids take the form of the container that contains them. For this we use the following list:
1 l = 1 dm3
Measure conversion table
The same method can be used to calculate various quantities.
First, let's draw a table and place in its center the base measurement units of the quantities we want to convert, for example:
- Capacity: liter (l)
- Length: meter (m)
- Mass: gram (g)
- Volume: cubic meter (m3)
Everything on the right side of the base measure is called submultiples. The prefixes deci, centi and milli correspond respectively to the tenth, hundredth and thousandth part of the fundamental unit.
On the left side are the multiples. The prefixes deca, hecto and kilo correspond respectively to ten, one hundred and one thousand times the fundamental unit.
| multiples | Base Measure | submultiples | ||||
|---|---|---|---|---|---|---|
| kilo (k) | hecto(h) | decade) | I decided (d) | centi (c) | milli (m) | |
| kiloliter (kl) | hectoliter (hl) | dekaliter (dal) | liter (l) | deciliter (dl) | centiliter (cl) | milliliter (ml) |
| kilometer (km) | hectometer (hm) | dekameter (dam) | meter (m) | decimeter (dm) | centimeter (cm) | millimeter (ml) |
| kilogram (kg) | hectogram (hg) | decagram (dag) | gram (g) | decigram (dg) | centigram (cg) | milligram (mg) |
| cubic kilometer (km3) | cubic hectometer (hm3) | cubic decameter (dam3) | cubic meter (m3) | cubic decimeter (dm3) | cubic centimeter (cm3) | cubic millimeter (mm3) |
know more about Unit Conversion.
Examples
1) How many milliliters correspond to 35 liters?
To make the requested transformation, let's write the number in the capacity measures table. Remembering that the measure can be written as 35.0 liters. The comma and the digit before it must be in the place of the given unit of measure, which in this case is the liter.
| kl | hl | from there | there | dl | cl | ml |
|---|---|---|---|---|---|---|
| 3 | 5, | 0 |
Then we complete the other boxes with zeros until we reach the requested unit. The comma will always be behind the digit that is in the requested unit box, which in this case is the ml.
| kl | hl | from there | there | dl | cl | ml |
|---|---|---|---|---|---|---|
| 3 | 5 | 0 | 0 | 0, |
Thus 35 liters corresponds to 35000 ml.
2) Transform 700 grams into kilograms.
Remembering that we can write 700.0 g. We put the comma and the 0 before it in the given unit, in this case g and the other digits in the previous places
| kg | hg | dag | g | dg | cg | mg |
| 7 | 0 | 0, | 0 |
Then we complete it with zeros until we reach the unit requested, which in this case is the kilogram. The comma then passes behind the figure in the kilogram place.
| kg | hg | dag | g | dg | cg | mg |
| 0, | 7 | 0 | 0 |
So 700 g corresponds to 0.7 kg.
3) How many cubic meters are there in a 4500 cubic centimeter parallelepiped?
In volume transformations (m3), we will proceed in the same way as in the previous examples. However, we must put 3 digits in each box.
We write the measurement as 4500.0 cm3.
| km3 | hm3 | dam3 | m3 | dm3 | cm3 | mm3 |
| 4 | 500, | 0 |
Now we complete each box with 3 digits until we reach the requested unit.
| km3 | hm3 | dam3 | m3 | dm3 | cm3 | mm3 |
| 000, | 004 | 500 |
We found that 4500 cm3 correspond to 0.0045 m3.
What about Time?
The base unit of measure of time in the SI is the second(s). The second is currently defined as the time duration of 9,192,631,770 vibrations of the radiation emitted by the electronic transition between the hyperfine levels of the ground state of the cesium 133 atom.
The multiples of the second are the minute, hour and day. These measurements are not decimal, so the following relationships are used:
1 minute (min) = 60 seconds (s)
1 hour = 3600 seconds (s)
60 minutes (min) = 1 hour (h)
24 hours (h) = 1 day (d)
The submultiples of the second are:
Tenth of a second = 0.1 s or 1/10 s
Hundredth of a second = 0.01 s or 1/100 s
Thousandth of a second = 0.001 s or 1/1000 s
There is a unit of measurement used in Astronomy to indicate enormous distances.
Learn more at:
- International System of Units
- Light year: What is it and how to Calculate
- Time Measurements
- How to Turn Minutes into Hours