Hands-on Activity Give an Inch, Take a Foot

Learning Objectives

After this activity, students should be able to:

• Explain why accuracy in measurement is important to engineering.
• Describe how to read a meter stick or ruler using the units in the metric system.
• Use the correct metric system units to measure different distances.

Educational Standards

Each TeachEngineering lesson or activity is correlated to one or more K-12 science, technology, engineering or math (STEM) educational standards.

All 100,000+ K-12 STEM standards covered in TeachEngineering are collected, maintained and packaged by the Achievement Standards Network (ASN), a project of D2L (www.achievementstandards.org).

In the ASN, standards are hierarchically structured: first by source; e.g., by state; within source by type; e.g., science or mathematics; within type by subtype, then by grade, etc.

NGSS: Next Generation Science Standards - Science

Common Core State Standards - Math

International Technology and Engineering Educators Association - Technology

State Standards

Materials List

Each group needs:

• 2 rulers with metric units (one for each student)
• 2 of the same "measuring strips" off of the Secret Partners Worksheet

To share with the entire class:

• 2 or 3 meter sticks
• 3 pieces of string of different lengths
• 3 text books, labeled #1, #2, and #3

Worksheets and Attachments

Pre-Req Knowledge

Students should have some prior experience with the following terms: mass, distance, length and volume.

Introduction/Motivation

Do you know how tall you are? Can you estimate how tall I am? Estimation is a guess that is often done before an actual measurement (Write some of their estimations on the board. Answers will probably be in English units such as feet; encourage estimations in metric units.) How can we figure out how tall we actually are? That's right, we could measure our heights. What would we use to do that? Maybe we would use a ruler, or a measuring tape, or even a meter stick. These are some devices that engineers use to measure distances and sizes of objects.

What is a measurement? A measurement for our activity today is a number value given to a property of an object, such as distance, mass or volume. A system of measurement is a group of units that are used for measuring something, such as meters or pounds. The metric system is the most common system used for measurement in the world so it is important that engineers know the units of this system in order to communicate with people in other cities or countries!

Today we are going to practice using the metric system to measure distances in the classroom. The unit used for measuring distance is the meter. There are 1,000 meters in a kilometer, so a kilometer is used to measure larger distances. There are 100 centimeters in one meter, so a centimeter is used to measure small objects and small distances. An even smaller unit of measurement is the millimeter; there are 1,000 millimeters in one meter!

How would you measure my height? [Allow students to respond. Have two students each measure the height of the teacher using a meter stick and write their results on the board; remember to label the units (meters). Discuss the methods the students used to arrive at their answer and also acknowledge if the measurements were the same or different.] Why might these two measurements be different? (Possible answers: There were small differences in how the students each took the measurements; there were small differences in how the students read the meter stick.)

Can you think of some distances that engineers may measure using kilometers, meters, centimeters or millimeters? (Possible answers may include: Environmental engineers may measure the distance of a river in kilometers, a civil engineer might measures the height of a building, an aeronautical engineer may measure the height of a rocket in meters, biomedical engineers may measure the size of a cell in millimeters or the length of a bone in centimeters.) These are all great examples!

We just talked about why two measurements of the same object might be slightly different. Do you know why it is important for engineers to make accurate measurements? Think about what could happen if an engineer were to make a mistake when she designed a bridge to stretch across a river. If the engineer measured the distance across the river and her measurement was too short, the civil engineers would not be able to reach the other side of the river with the bridge and it would have to be designed again. A lot of time and money would be wasted

Also, what would happen if a biomedical or chemical engineer working on developing a certain type of medicine was using a recipe from an engineer in another country who was not accurate in measuring the amounts of the chemicals? What might happen if they added a little too much of a certain chemical to the new medicine? Instead of that medicine making people well, it might actually make people even sicker. This is why it is important for engineers to practice good measuring techniques and be able to share their results with other engineers. Are you ready to practice your measurement skills? Let's get started!

Procedure

Background

There are many useful prefixes and conversions of units; knowing these units will help students understand measurements.

Imperial to Metric Conversion (approximations):

1 pound (lb) = 0.454 kilograms (kg) = 454 grams (g)

1 foot (ft) = 0.305 meters (m)

1 mile (mi) = 1.61 kilometers (km)

1 inch (in) = 2.54 centimeters (cm)

1 gallon (gal) = 3.78 liters (l)

1 ounce (oz) = 29.6 milliliters (ml)

Metric to Imperial Conversions (approximations):

1 kilogram (kg) = 2.21 pounds (lbs)

1 meter (m) = 3.28 feet

1 kilometer (km) = 0.621 miles (mi)

1 centimeter = 0.394 inches (in)

1 liter = 0.265 gallons (g)

1 milliliter (ml) = .0338 ounces (oz)

Before the Activity

1. Make four copies of the Secret Partners Worksheet, so that after each worksheet is cut into strips (as indicated by the separate boxes on the worksheet), the same strips can be given to either four individual students or two specific student pairs.
2. Gather enough rulers with metric units for each student.
3. Collect several meter sticks (students can share).

With the Students

1. Distribute the Secret Partners Worksheet strips so that there are two of the same strip of worksheet among four random students or two specific students pairs. The strips can be identified by the pictures.
2. Allow time for students to make the measurements specified on their worksheet strips. Make sure the measurements are in metric units and that all measurements are properly labeled with kilometer (km), meter (m), centimeter (cm), or millimeter (mm). Instruct them to wait to answer the last question on their worksheet strip.
3. Once all of the students have made their own measurements, tell the students to find their "secret partners" by finding the students or pair with the same worksheet strip (that is, the worksheet with the same picture).
4. Once the partners have been located, allow students to compare their answers. Have them answer the questions at the bottom of the page about why it is important for engineers to make accurate measurements.
5. As a class, create a class tally of the measurements. (Note: A Class Tally Template is provided as an overhead; attached.) Discuss the results. How similar were the measurements for each object?
6. (Optional) If time allows, have the students complete the Engineering Design Post-Assessment in which they are asked to think about what products might need to use the measurements they just made and create a sketch of an example product.

Vocabulary/Definitions

estimation: An educated guess.

measurement: An estimation of a certain property of an object.

meter: A fundamental unit of distance measurement in the metric system.

Assessment

Pre-Activity Assessment

Estimation: Have the students estimate the height of their teacher (in meters). Have students estimate the length of their foot (in centimeters). Share answers with the class.

Brainstorming: Have the students engage in open discussion to think of the different distances and sizes of objects that engineers measure. Remind students that no idea or suggestion is "silly." All ideas should be respectfully heard.

Activity Embedded Assessment

Secret Partners Worksheet: Have the students complete the Secret Partners Worksheet taking all measurements in metric units; review their answers to gauge their mastery of the subject.

Post-Activity Assessment

Communicating the Measurements: Have students compare their answers with their partner and answer the questions at the bottom of the Secret Partners Worksheet. Discuss the following as a class.

• Where their measurements the same as their partners for each item?
• Why is it important for engineers to take accurate measurements?

Engineering Design of Products: Have students think of reasons why an engineer would have to make the particular measurement that they just made on their Secret Partners Worksheet. For example, an engineer may need to measure the height of a person in order to design a spacesuit. It may also be important to measure the length of a book in order to create a new type of backpack. Have the two partners share their ideas with the rest of the class; or have them expand on one of their ideas and design a new spacesuit or backpack using the measurements they have recorded.

Estimation Revisited: Have students measure the actual distance of the foot they estimated before the activity. How close was their estimation to their measurement? When might an estimation be used in engineering design?

Worksheet Revisited: Have students convert their measurements to meters. Discuss how measurements can be expressed in larger units in terms of smaller units and how it is often helpful to do so for certain circumstances (e.g., for larger objects, expressing in meters might be more useful, however for smaller objects centimeters are more useful).

Troubleshooting Tips

If not all of the items on the worksheets are available in the classroom, provide the students with alternate items to measure in meters or centimeters.

Activity Extensions

Have students learn more about the prefixes used in measurement. Engage the class in a discussion of metric system prefixes and ask them to list the following units in order from smallest to largest: meter, centimeter, kilometer, millimeter.

Activity Scaling

• For upper grades, include more measurement of the object in addition to distance, such as mass and volume (if appropriate).

Copyright

Contributors

Supporting Program

Acknowledgements

The contents of these digital library curricula were developed by the Integrated Teaching and Learning Program under National Science Foundation GK-12 grant no. 0338326. However, these contents do not necessarily represent the policies of the National Science Foundation, and you should not assume endorsement by the federal government.