G4-Measurements Lower Level- 03

Would you buy a pizza without knowing the size? You would want to know what size pizza you would get for your money (small, medium, or large). Just as you would want fair trade, people throughout history wanted the same. To have fair trade among people, units needed to be made.

Units of measurements were gotten in many ways. Egyptians and Babylonians used their body. For instance, hands, fingers, and forearms were used. This method caused problems as one person’s hand or arm may have been a different size from another’s. As travel and trade grew, standard units of measurement were needed. These new units helped with trade across different areas and cultures. From these early beginnings, our system was founded. In science, the standard measurement system is the Metric System.

Although the metric system is more commonly used worldwide, the United States remains a holdout. For most everyday things in the United States, measurement is done in what is called “English units.” You already know that inches, feet, yards, and miles tell length. There are also ounces and pounds that tell weight. Quarts and gallons are used to tell liquid volume. These are the units often used in the United States.

As you might imagine, using different units can cause problems. This was the case with NASA’s Mars orbiter, when different units (English vs. Metric) were used. The result was a total loss of the orbiter, which cost $125 million. Even though errors may seem small, the cost of the small errors can be huge.Can you think of a time where using different measurement units could cause a problem? With practice, you will learn about units. You will learn the metric system. It is needed to know the value of including units with all measurements. Scientists must learn to work with other scientists.

Scientists will want to repeat the work of other scientists. To do so, it will need detailed notes of the study and include units for all the amounts. Clear reporting about units is critical. Learning to apply the right measurement units is critical to doing science the right way.