Centuries ago, people came up with standard measures of length. For example, the Egyptians used body parts as their units of measure (e.g., a foot to measure a foot and a thumb to measure an inch). The only problem was that people’s feet and thumbs were different sizes. They also had ways to measure weight, temperature, and liquid volume.

Following the Egyptian system for weights and measurements, the Imperial system (developed in England) made one update to include standard units so one foot was a specific length (12 inches or 0.3048 meters). The Imperial system is based on the inch / foot / yard / mile (length), the ounce / pound (weight) and the fluid ounce / pint / quart / gallon (volume).  

While only the United States and two other countries use the Imperial system, the rest of the world uses the Metric system (developed by France). The word metric comes from the Greek word “metre” meaning to measure and it includes a set of prefixes for making things bigger (kilo- , mega- , giga- , tera- ) or smaller (milli- , micro- , nano- ) in multiples of 1000.  

Use your math knowledge and skills to identify the difference between the Metric and Imperial systems in your daily life and come to your own conclusion about which system you like best.  

Tools 

• Writing utensil and piece of paper 

• Measurement Worksheet (forthcoming)

• Length Measuring Tool (Ruler or Tape Measure) 

• Imperial vs. Metric Infographic 

• Metric System vs. Imperial System: Differences and Use  

Steps  

Step 1: To learn more about the two measurement systems, read the infographic (see in the Tools sections) and reread the introduction to get a basic understanding of the two measurement systems. In the next three steps, you will test both systems to see which is more intuitive or easier for you to understand and use.  

Step 2: Before you measure, you will need to create a document to record all measurements. On a piece of paper, draw three columns. Add one row at the top and label each column in that row as “Object,” "Imperial,” and “Metric.” 

Step 3: You will investigate how length measurements differ between both measurement systems. Find your measurement tool (a ruler or tape measure) and check to make sure that one side shows inches/feet and the opposite side shows centimeters/meters. Now search around your house and select several different objects to measure. Be sure to include both short objects like your thumb or foot and tall/long objects like you (your height) or a door. List each object in its own row down the first column.

Step 4: Measure each object using both sides of your measurement tool and record the length or height in their specific columns. Be sure to include the units so that the Imperial column has “feet and inches” and the Metric column has “centimeters and meters.”

Step 5: Once you have completed all your measurements, have a discussion with a friend, an adult, your family, or your classmates about the measurements you took. What do you notice when you compare the Imperial measurements with the Metric measurements? Does one system make more sense to you? If you were going to look at an object and estimate its length, which measuring system would be easier to use when making your best guess? 

To Do or Learn More:  

• After this activity, can you estimate the length or height of an object without measuring it? Test your newfound measuring skills by estimating different objects’ heights or lengths and then actually measuring those objects. How well can you estimate?

• If you are up for a challenge: explore other differences in measurements between Imperial and Metric including weight, volume/capacity, and temperature! Use this Measure It activity to inspire you to create individual comparison charts, like you did for length, for the different measurements of weight, volume, and temperature.   

• Have you heard of the Metric Conversion Act of 1975? Congress designated the Metric system as the preferred system of weights and measures for U.S. trade and commerce, and directed federal agencies to convert to the Metric system. The National Institute of Standards and Technology (NIST) aims to make the U.S. more competitive by maintaining this conversion policy. Their efforts can be seen today because the U.S. teaches and uses both measuring systems in the sciences, technology, engineering, and math fields.

• Why Doesn't the U.S. Use the Metric System? Watch this video by Today I Found Out to understand why the U.S. is inching towards the Metric system.