Chapter Outline

Measurement

There are two main systems for measuring distance, weight, and liquid capacity:

• The United States and parts of the former British Empire use customary, or standard, units of measurement.
• Most other countries use the metric system.

Customary Measures

The following are customary measures of length:

• inches
• feet
• yards
• miles

The following are customary measures of weight:

• ounces
• pounds
• tons

The following are customary liquid measures:

• ounces
• cups
• pints
• quarts
• gallons

The following are customary measures of time:

• seconds
• minutes
• hours
• days
• weeks
• years

The following are rules of conversion for customary units of measure:

• To change from a smaller unit of measure to a larger unit, divide.
• To change from a larger unit of measure to a smaller unit, multiply.

Metric Measures

The metric system has three basic units:

• The basic unit of length is the meter.
• The basic unit of weight is the gram.
• The basic unit of liquid measure is the liter.

All other units are formed by adding a prefix to the base unit:

• kilo- = 1,000 × base unit
• hecto- = 100 × base unit
• deca- = 10 × base unit
• deci- = 0.1 × base unit
• centi- = 0.01 × base unit
• milli- = 0.001 × base unit

The following are rules of conversion for metric measures:

• To change from a smaller unit to a larger unit, divide. The decimal point will move to the left.
• To change from a larger unit to a smaller unit, multiply. The decimal point will move to the right.

Converting Measurements

• One unit of measure can be changed to another by setting up a proportion.
• It is possible to convert customary units of measure to metric units and vice versa.

Scales, Meters, and Gauges

The following tools are used for different types of measurement:

• A ruler is used to measure short distances.
• Gauges are used to measure mileage, temperature, speed, current, pressure, and so on.