# Weights and Measurements

print

Let’s say you wanted to tell a friend how large your dog was. You had never heard of inches or feet. How could you explain it? Thousands of years ago, people used common objects to describe and compare measurements.

You could use your hand as a measuring tool, i.e., “My dog is 8 hands tall.” You could use natural objects that were generally the same size, e.g., sea shells or an ear of corn. These measurements wouldn’t be as exact as using a ruler with inches and feet, but they could help you make a general comparison.

Fun Facts

• In the U.S., we use inches, feet, cups, and ounces as our form of measurement. Almost everywhere else, people use the metric system, which includes centimeters, meters, and liters.
• Thermometers measure temperature. In the U.S., we use Fahrenheit measurements; the metric system uses Celsius measurements.
• Weight is different than mass. Weight is measured in pounds and describes the force of gravity an object has. Mass measures the number of atoms in an object.
• Length and height measure how tall and wide something is. Area measures how many inches or feet are in a certain space, such as a yard or room. Volume, measured in quarts or gallons, refers to how much of something fits in a container, such as a measuring cup or pitcher.

Vocabulary

Thermometer: a device used to measure how hot or cold something is

Scale: a device used to determine an object’s weight

Mass: the number of atoms something has

Q and A

Question: Why is it important to have accurate measurements?

Answer: Sometimes a general estimate works just fine, as in, “My dog is about 8 hands tall.” But what if you were building something? You need to know exactly how many inches or feet to cut the wood or your project won’t turn out right. How about taking medicine? You need to know exactly how much the doctor wants you to take. Taking too much medicine might make you sick.

Question: How can I learn about measurement at home?

Answer: Use a standard measurement, such as a ruler or scale, to measure and weigh items around your house. Now use a non-standard measurement, such as a block or your hand. Record your results.