In all areas of STEM, understanding units of measurement is vital.
Metric vs. Imperial Units
While most of the world uses the metric system, the United States (along with Myanmar and Liberia) uses imperial units. Because STEM is a global field with research and publications coming from a variety of sources, it is still important to have at least a basic understanding of each system. This unit focuses on the names, abbreviations and pronunciations for common units of measurement.
Linear Measurements
| Metric | |
|---|---|
| Millimeter | mm |
| Centimeter | cm |
| Meter | m |
| Kilometer | km |
| Imperial (US) | |
|---|---|
| Inch (2.54 cm) | in |
| Foot* (30.48 cm) | ft |
| Yard (.91 m) | yd |
| Mile (1.61 km) | mi |
*“Foot” has the irregular plural “feet.”
Weight Measurements
| Metric | |
|---|---|
| Gram | g |
| Kilogram | kg |
| Imperial (US) | |
|---|---|
| Ounce (28.35 g) | oz |
| Pound (.45 kg) | lb |
Liquid Measurements**
| Metric | |
|---|---|
| Milliliter*** | mL |
| Liter | L |
| Imperial (US) | |
|---|---|
| Fluid ounce (29.57 mL) | fl oz |
| Gallon (3.79 L) | gal |
**There are many more measurements for liquid and volume used in cooking (tablespoons, pints, etc.), but they are not typically used for STEM.
***Some industries (particularly medical) use cubic centimeters (cc) instead of milliliters. These units are interchangeable (1 mL = 1 cc).
Two Important Pronunciation Notes
- Abbreviations are for written form only. When speaking, say the whole word aloud even if you only see the abbreviation.
- If the abbreviation is being used as an adjective, it will be singular. If the abbreviation is being used as a noun, it will be plural (unless it is exactly one unit).
Examples
- He bought a 12 oz bag of marshmallows. (He bought a twelve ounce bag of marshmallows.)
- He bought 12 oz of marshmallows. (He bought twelve ounces of marshmallows.)
- She ran a 42.2 km marathon. (She ran a forty-two point two kilometer marathon.)
- She ran 42.2 km. (She ran forty-two point two kilometers.)
Exercise
Open the exercise to begin the activity. Follow the instructions in the document.