University of Virginia
Physics Department

## Metric Measurement

A Physical Science Activity

2003 Virginia SOLs

• PS.1

Objectives

Students will

• sense the value of uniform measurement standards;
• accurately use a metric ruler;
• accurately read and record measurements in centimeters and millimeters;
• use the following skills: measuring, collecting and interpreting data.

Background Information

Measurement is an important skill in science that facilitates accurate communication. It is important to understand that measurements cannot be useful without standards. A standard is an exact quantity that people agree on for comparison. Explain to students that an early standard used for measuring length was the hand span. Ask if they can think of any pros and cons for using the hand as a standard of measurement. They should see that the hand is something common to every one but that not all hands are the same size.

All measurements must have a number and a unit. The unit is the standard of comparison for that measurement. In the metric system the standard for measurement of length is the meter. One meter is 1/100,000,000 of the distance between the earth's north and south poles. When measuring distances, it is helpful to use standards that are somewhat close to the distance you are trying to measure. For this reason the meter is divided into 100 smaller pieces, centimeters (cm). For even smaller distances the centimeter is divided into 10 smaller units, millimeter (mm). It is important that the correct standard be used for the distance being measured.

### Student Activity

Part 1 - Standard Measurements of Length

Materials

• Meter stick

Procedure

1. The instructor will provide your group with several distances to measure. Measure them first in paces, then in meters. Enter your distances in the data table below and on the board.

Data Sheet

 Description Paces Meters

Part 2 - The Centimeter and Millimeter

Materials

• 30 cm metric ruler

Procedure

1. Complete the following Data Sheet

Data Sheet

1. The diagram below represents a portion of the centimeter ruler between 16 and 17 centimeters. Fill in the answers for (A) and (B) to make sure that you know how to use a ruler.

 A. ____________ cm ___________ mm B. ____________ cm ___________ mm

2. Measure and record the following data:

 Objects Measured Centimeters (cm) Millimeters (mm) Pencil Book Width Book Length Book Height Shoe Length Index Finger Width at Knuckle

3. Find the area of the rectangle. First measure the length and width, then multiply the length and width together (A = L x W).

 Length ______cm     Width ______cm     Area ______cm2 Length ______mm     Width ______mm     Area ______mm2

4. How do you convert a measurement from centimeters to millimeters?

5. How do you convert a measurement from millimeters to centimeters?

Part 3 - The Metric Smile

Materials

• metric ruler

Procedure

1. Each person in your group will measure and record the length of the smile of each other person in that group.
2. Make sure your results agree with everyone else's. If there are discrepancies check your measurements again.
3. When accurate results are obtained record them in the table from least to greatest.

Data Sheet

 Name Smile Length (cm)

Students with Special Needs

Each student should be able to participate in this activity.

Click here for further information on laboratories with students with special needs.

Assessment

1. Did any of your measurements agree with measurements of the other groups? Which ones agreed?

2. Which method of measurement gave the widest range of measurements?

3. What reason can you give for these differences in measurements?