Mass is the amount of matter contained in an object. The mass of an object is usually measured using a weight scale.
The more matter there is in an object, the greater its mass will be. Thus, the force required to move it will be greater. It is important not to rely on the volume of an object to estimate its mass. For example, a brick has a greater mass than a pillow even though its volume is smaller.
The basic unit of measure for mass in the International System of Units is the kilogram (kg).
Here is a table of the most commonly used units for measuring mass:
|
Prefix |
Kilo- |
Hecto- |
Deca- |
|
Deci- |
Centi- |
Milli- |
|
Mass |
Kilogramme (kg) |
Hectogram (hg) |
Decagram (dag) |
Gram (g) |
Decigram (dg) |
Centigram (cg) |
Milligram (mg) |
|
Equivalent value to 1 g |
0.001 kg |
0.01 hg |
0.1 dag |
1 g |
10 dg |
100 cg |
1 000 mg |
In this table, each unit is 10 times larger than the unit that follows it. Thus, 1 gram is 10 decigrams, 1 decigram is 10 centigrams, etc.
Converting a unit of measurement involves expressing a quantity in a larger or smaller unit of measurement.
The “jump” method or a metric conversion table can be used to convert one measurement to another.
According to this method, it is necessary to:
-
Multiply the unit by 10 when converting it to a smaller unit
-
Divide the unit by 10 when converting it to a larger unit.
Multiply or divide by 10 for each “jump” or unit change.
For example, to convert cg to mg, multiply by 10. Conversely, to convert mg into cg, divide by 10.
When moving units to the right, multiply by 10 for each jump. When moving to units to the left, divide by 10 for each jump.
-
Milligrams ÷ 10 = centigrams
- 10 mg = 1 cg -
Milligrams ÷ 100 = decigrams
- 100 mg = 1 dg -
Milligrams ÷ 1 000 = grams
- 1 000 mg = 1 g -
Milligrams ÷ 1 000 000 = kilograms
- 1 000 000 mg = 1 kg
A metric conversion table can also be used to move from one unit of measure to another.
According to this method, it is necessary to:
-
Place the ones digit of the number in the position of the given unit of measurement and the other numbers to the left of it.
-
Put a 0 in each column up to the column of the new unit of measurement.
To convert 34 grams into centigrams, place the digit located in the ones position (4) in the grams column (starting unit of measurement). Next, place the 3 in the decagrams column. Finally, simply put 0s in each column up to the centigrams column (new unit of measurement).
The result is 3 400 cg.
There must be a digit in every column up to the new unit of measurement.
To convert 7 centigrams to grams, place the number 7 in the centigrams column (starting unit of measurement). Next, a 0 is added in each column up to the grams column (the new unit of measurement). Finally, a decimal point is added in the grams column.
The result is 0.07 g.
Mass is often measured in pounds. There is a mathematical operation to convert kilograms to pounds:
Pounds |\approx| Kilograms x 2.2
Kilograms |\approx| Pounds / 2.2
To understand the difference between mass and weight, consult the following concept sheet: Mass and Weight.