*Developed by Emily T.*

*Edited by Maggie M.* and Miranda C.

**Essential Question**

*How do units of measurement relate to each other? *

**Background Knowledge**

Students should know how to use a ruler to measure and should be able to differentiate between units (inches/centimeters).

Inches are American Standard units of length. Centimeters are a part of the metric system, also as units of length.

**Materials**

- ruler
- pencil
- paperclip
- 1 piece of paper
- 1 small book
- a material that could be used as a nonstandard unit

**Safety Protocol **

Ask parents/guardians for permission before completing this activity.

**Activity Procedures**

**Step 1: **Gather materials and make a chart to record the measurements (see chart below in “Resources”).** **If you did not have a ruler, how could you measure an object? Could you make up your own measurement system? For example, you could use the length of your thumb as a measurement. If I was using my thumb as a nonstandard unit, I would measure the length of my phone as three thumbs. For this lesson, you will identify a nonstandard unit of your own to measure objects!

**What nonstandard unit are you going to use to measure objects? **

**Step 2:** Now, let’s use a standard unit for measuring. For example, look at your ruler. What do you notice about the numbers on both sides of the ruler? Record what you notice about the two units of measurement on the ruler. Both of the units of measurements on a ruler are accepted by the United States are a standard unit, meaning that everyone uses them!

**Which unit of measurement is the biggest? Which is the smallest? **

**Step 3: **Use the ruler to measure the length of the pencil from the eraser to the point. Record the measurement in inches, measure it again in centimeters, and finally measure the pencil in the nonstandard unit you have chosen. Record the measurements in your chart.

**Why is the number of measured inches smaller than the number of measured centimeters for the same object? **

**Step 4: **Use the ruler to measure the length of the paperclip, piece of paper, and small book. Record the length in both inches, centimeters, and your nonstandard unit.

**Why is the number of centimeters greater than the number of inches?**

**How does the standard measurement compare to your nonstandard measurement?**

**Step 5: **Choose one object that you measured. Look at your measurements for that object. How much bigger is an inch than a centimeter?

**Why do we need different units of measurement?**

**Which unit of measurement worked better for smaller objects?**

**Which unit of measurement worked better for bigger objects?**

**How can we use measurement to decide where to store/keep objects?**

**Step 6: **With parent/guardian permission, share the results of your activity on social media using #AUHomeWorks!

**Resources**

Object | Nonstandard Units | Length in Inches | Length in Centimeters |

Pencil | |||

Paperclip | |||

Piece of paper | |||

Small book |

Last modified: January 14, 2021