DDD.3 Use abbreviations for customary and metric units of measurement
What are abbreviations?
Abbreviations are shortened forms of words. They are used to save space and make writing quicker while keeping the same meaning.
- inch → in.
- minute → min
- pound → lb
Abbreviations should be easy to understand and are often used in math, science, and everyday writing.
Abbreviations for customary units of measurement
Customary units of measurement are commonly used in the United States to measure length, weight, and capacity. These units often have standard abbreviations.
- inch → in.
- foot → ft
- yard → yd
- mile → mi
- pound → lb
- gallon → gal
Some customary abbreviations use periods, and some do not. Follow the most common form shown in your lessons.
Abbreviations for metric units of measurement
Metric units of measurement are used around the world and are often used in science. Their abbreviations are standard and usually do not include periods.
- millimeter → mm
- centimeter → cm
- meter → m
- kilometer → km
- gram → g
- liter → L
Metric abbreviations are written in lowercase letters, except for L for liter to avoid confusion.
Using measurement abbreviations correctly
Measurement abbreviations are used after numbers to show what is being measured. A space is usually placed between the number and the abbreviation.
- The pencil is 6 in. long.
- The bottle holds 2 L of water.
- The dog weighs 45 lb.
Do not pluralize abbreviations. The abbreviation stays the same, even if the number is more than one.
When to use abbreviations
Abbreviations are often used in charts, labels, instructions, and informational writing. In sentences, they should be clear and easy to read.
- The race is 5 km long.
- Add 1 tsp of salt.
- The board is 3 ft wide.
If you are unsure whether to use an abbreviation, think about whether it will help the reader understand the measurement.