• Use metric prefixes to convert units and solve problems
• Convert between U.S. customary and metric units of length, weight/mass, and volume
• Convert between different temperature scales using conversion formulas

What is Metric?

The metric system is a standardized system of measurement based on the International System of Units (SI), which is used worldwide for scientific and everyday measurements. It’s a decimal-based system, designed to be logical and easy to use, where each unit is a multiple or a fraction of ten of the base unit. This simplification facilitates the conversion between units and calculations, as it requires only the movement of the decimal point without complex multiplication or division.

The system encompasses units for various physical quantities. For example, for length, the meter is the base unit; for volume, the liter; and for mass, the gram. Each of these can be scaled up or down using prefixes like kilo, centi, and milli, which denote multiplication by a thousand, a hundredth, and a thousandth, respectively.

the metric system

The metric system uses the base units meter, liter, and gram to measure length, liquid volume, and mass.

 

The metric system is based on [latex]10[/latex]s, meaning units within the system get larger or smaller by a power of [latex]10[/latex].

Though it is rarely necessary to convert between the customary and metric systems, sometimes it helps to have a mental image of how large or small some units are. The table below shows the relationship between some common units in both systems.

	Common Measurements in Customary and Metric Systems
Length	[latex]1[/latex] centimeter is a little less than half an inch.
	[latex]1.6[/latex] kilometers is about [latex]1[/latex] mile.
	[latex]1[/latex] meter is about [latex]3[/latex] inches longer than [latex]1[/latex] yard.
Mass	[latex]1[/latex] kilogram is a little more than [latex]2[/latex] pounds.
	[latex]28[/latex] grams is about the same as [latex]1[/latex] ounce.
Volume	[latex]1[/latex] liter is a little more than [latex]1[/latex] quart.
	[latex]4[/latex] liters is a little more than [latex]1[/latex] gallon.

 

You can view the transcript for “Why the metric system matters – Matt Anticole” here (opens in new window).

Prefixes in the Metric System

The metric system is a base [latex]10[/latex] system. This means that each successive unit is [latex]10[/latex] times larger than the previous one.

The names of metric units are formed by adding a prefix. to the basic unit of measurement. To tell how large or small a unit is, you look at the prefix. To tell whether the unit is measuring length, mass, or volume, you look at the base.

prefixes in the metric system

Metric Prefix	Meaning
kilo-	[latex]1000[/latex] times larger than base unit
hecto-	[latex]100[/latex] times larger than base unit
deka-	[latex]10[/latex] times larger than base unit
(No prefix)	Base units (gram, meter, liter)
deci-	[latex]10[/latex] times smaller than base unit
centi-	[latex]100[/latex] times smaller than base unit
milli-	[latex]1000[/latex] times smaller than base unit

Using this table as a reference, you can see the following:

• A kilogram is [latex]1,000[/latex] times larger than one gram (so [latex]1[/latex] kilogram [latex]= 1,000[/latex] grams).
• A centimeter is [latex]100[/latex] times smaller than one meter (so [latex]1[/latex] meter [latex]= 100[/latex] centimeters).
• A dekaliter is [latex]10[/latex] times larger than one liter (so [latex]1[/latex] dekaliter [latex]= 10[/latex] liters).

Here is a similar table that just shows the metric units of measurement for mass, along with their size relative to [latex]1[/latex] gram (the base unit). The common abbreviations for these metric units have been included as well.

 

Since the prefixes remain constant through the metric system, you could create similar charts for length and volume. The prefixes have the same meanings whether they are attached to the units of length (meter), mass (gram), or volume (liter).