Conventional measures

785
David Holt
Conventional measures

What are conventional measures?

The conventional measures are those that are made using a measurement pattern accepted and recognized by most people, which are called standard patterns of measure.

This is very convenient, since if everyone knows the pattern, when communicating the result of a measurement it will be immediately understandable to anyone.

One of the most used patterns is the meter (m), which belongs to the decimal metric system.

In every home there is a tape measure to measure countless things: the height and contour of people or the dimensions of objects. If, for example, someone measures the length of a table and gets a reading of 1.30 m, everyone who knows what a meter is immediately knows the exact length of the table, even if it is not in front of him..

In addition to lengths, there are other common measurements in the home, office, or workshop. At home, when preparing a recipe by following the steps exactly, you have to weigh the solid ingredients and measure the volume of the liquids.

For its part, the cooking time is also important, so it must also be measured carefully.

Measurements of mass, capacity, length and time have been measured with great frequency in the everyday and technical sphere, since time immemorial..

What are the conventional measures?

1. Mass

Mass is related to the amount of matter an object has and also to its weight. It is important to note that mass and weight are different quantities, although they are often confused. The weight of a body has to do with how much force the Earth exerts on it, drawing it towards the surface.

The bodies with more mass are attracted with greater force, therefore their weight will be greater. Both the mass and the magnitude of the weight are proportional quantities, but by carefully choosing an appropriate system of units, their magnitudes can be made to coincide, numerically speaking..

In most countries, the standard used to measure mass is the kilogram (kg), being common to find that foods are measured with this pattern. People also use it to establish their weight and therefore their mass.

The kilogram is one of the multiples of the gram, which is the central unit for measuring mass and is also widely used in family kitchens..

  • Small masses

Submultiples of the gram, such as milligram (mg), They are also widely used, but they are more appropriate standards for measuring very small masses (a milligram is one thousandth of a gram).

  • Main units of mass
    • grams (g)
    • kilogram (kg) = 1000 grams
    • hectogram (hg) = 100 grams
    • decagram (dag) = 10 grams
    • decigram (dg) = tenth of a gram
    • centigram (cg) = hundredth of a gram
    • milligram (mg) = one thousandth of a gram

2. Length

100 centimeters is a meter

The standard pattern for lengths is meter (m). When you want to measure the width of a table, for example, the zero of the tape measure is placed on one end of the table, and the tape is extended until it reaches the other end, observing the value indicated. This is the desired measure.

To measure close and familiar objects, the height of people, the dimensions of a room or the height of the ceiling, the meter is a very suitable standard..

  • Small object lengths

The dimensions of smaller objects, such as a glass of water, a bank card or the dimensions of a chair, are determined by a submultiple of the meter called centimeter (cm). One centimeter equals one hundredth of a meter, therefore:

1m = 100cm

Homemade flexible measuring tapes are usually 1.5 meters long and have a scale divided into 150 cm on one side. In turn, the centimeters are divided into millimeters (mm), where 1 cm = 10 mm.

The tape measure usually has an inch scale on the other side. The inch is commonly used in the British system of units, it is equivalent to 2.54 cm and is currently still used as a measure of length in the United States.

  • Great lengths

If, on the other hand, what you want to measure is a much greater length, for example the distance between two cities, a multiple of the meter called kilometer is preferred. A kilometer (km) is equivalent to 1000 meters.

  • Main units of length

    • meter (m)
    • centimeter (cm) = hundredth of a meter
    • decimeter (dm) = tenth of a meter
    • millimeter (mm) = one thousandth of a meter
    • kilometer (km) = 1000 meters

3. Capacity units

Capacity is the volume occupied by a liquid (or a gas). For example, it is used to know how much liquid can be stored in an empty container.

The base unit of capacity is the liter (abbreviated L). For example, the containers of liquid milk, juices, wines and soft drinks, indicate on the label the liters they contain.

The milliliter (ml), is one thousandth of a liter and is used to measure smaller amounts of liquid, for example containers that contain individual servings.

If the liter is not an appropriate unit because the container is very large, such as a swimming pool or tank, then the hectoliter (HL), since 1 HL equals 100 L.

  • Main capacity units
    • liter (L)
    • milliliter (ml) = one thousandth of a liter
    • centiliter (cl) = hundredth of a liter
    • deciliter (dl) = tenth of a liter
    • decaliter (daL) = 10 liters
    • hectoliter (HL) = 100L
    • kiloliter (kL) = 1000L.

4. Units of time

There are many patterns for measuring time, depending on the length of the interval. Very short events are usually measured in seconds, the cooking time of many foods is measured in minutes, while the duration of a class can be a couple of hours.

The base unit for time is the second, however short it may be. In addition, there are the following patterns:

  •  24 hours = 1 day
  •  60 minutes = 1 hour
  • 1 minute = 60 seconds

If the time period is longer, such as the duration of a course, it is usually measured in weeks or months, like this:

  • 1 month = 30 or 31 days
  • 4 weeks = 1 month
  • 1 semester = 6 months or 24 weeks.
  • 1 trimester = 3 months or 12 weeks.
  • 1 year = 365 days.

The only month that does not have at least 30 days is February, which has 28 days or 29 in leap years (occurs every four years).

  • Main time units
    • seconds)
    • minute (min)
    • hour
    • day (24 hours)
    • week (7 days)
    • month (28,30,31 days)
    • decisecond (ds) = tenth of a second
    • centisecond (cs) = hundredth of a second
    • millisecond (ms) = thousandth of a second

References

  1. Easy Classroom. Time measurements. Recovered from: aulafacil.com.
  2. Magic World College. Conventional and unconventional measures. Recovered from: youtube.com.
  3. Specialized didactics. Didactic mathematics for preschool: Conventional units of measurement. Recovered from: youtube.com.
  4. Estimates and capacity measurement. Recovered from: edu.xunta.es.
  5. Mathematical articulation. Conventional and unconventional measures. Recovered from: contentsdigitales.ulp.edu.ar.

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