Introduction to MeasurementDeveloping Standard and Metric Measuring Skills

© 2011 Project Lead The Way, Inc.Design and Modeling

Why Learn to Measure?

Valuable skill for a job

Valuable skill for hobbies

Valuable skill for every day life

Measurement Systems

Two types of measurement systems exist.

– Standard (Customary)

- Metric (SI or International System)

Standard (Customary) System

Inches Fractions

2

4

8

16

¼ ¾

The Whole Inch

First Half Second Half

1/83/8

5/8 7/8

1/163/16

5/16 7/16

9/1611/16

13/16 15/16

1. Find out how many parts the inches are divided into.

Count the spaces in 1 inch.

This number will be the denominator.

2. Count the number of whole inches.

Write down the number.

3. Count the number of spaces after the last whole inch.

This number will be the numerator.

4. Reduce fraction, if necessary.

Steps in Using the

Standard (Customary) System

Step 1

Step 2

Step 3

Find Denominator

Count Whole Inches

Find Numerator

Step 4Reduce Fraction, If Necessary

Let’s Review

16

71

Let’s Practice

What is the distance from the end of the ruler to A?

What is the distance from the end of the ruler to E?

What is the distance from the end of the ruler to D?

What is the distance from the end of the ruler to C?

What is the distance from the end of the ruler to B?

𝟏 𝟒 in.

𝟏𝟓𝟏𝟔 in.

1 𝟑 𝟒 in.

2 𝟑 𝟖 in.

3 𝟏 𝟏𝟔 in.

Metric System

International System of Units (SI)

Millimeters and

Centimeters Decimals

1 mm = 0.1 cm

5 mm = 0.5 cm

10 mm = 1 cm

Steps in Using the

Metric (SI) System

1. Count the number of whole centimeters

(cm).These are the larger lines with numbers

2. Count the number of lines after the whole

number.

The smaller lines are millimeters (mm).

3. Put in correct terms.

Since mm are 1/10th of a cm, if you

measure 7 marks after 1 cm, the measure

is 1.7 cm or 17 mm long.

Let’s Practice

What is the distance from the end of the ruler to A?

What is the distance from the end of the ruler to E?

What is the distance from the end of the ruler to D?

What is the distance from the end of the ruler to C?

What is the distance from the end of the ruler to B?

4 mm = 0.4 cm

19 mm = 1.9 cm

37 mm = 3.7 cm

63 mm = 6.3 cm

73 mm = 7.3 cm

• Sometimes we need to know a measurement in

a unit different than the unit presented

• Conversion factor

o A ratio (fraction) that relates a measurement

in one unit to the same measurement in

another unit

o Example: To convert meters to centimeters

o Start with the equivalency 100 cm = 1 m

• The ratio of centimeters to meters is 100:1

•100 cm

1 mis the conversion factor

Unit Conversion

• feet to inches: 1 ft = 12 in.

◦ The ratio of inches to feet is 12:1

Desired Unit

Given Unit

• miles to feet: 1 mi = 5280 ft or

∘ The ratio of feet to miles is 5280:1

or12 in.1 ft

5280 ft

1 mi

Unit Conversion

• Conversion factor – Using a conversion factor to cancel unwanted units is

similar to canceling common factors when multiplying

fractions

5

7·7

3=

5

3

Unit Conversion

Example: Convert 17.2 yards to feet

17.2 yd

1X

3 ft1 yd

3 ft = 1 yd

= 51.6 ft

1= 51.6 ft

Unit Conversion

Example: Convert 17.2 yards to feet

17.2 yd

1X

3 ft1 yd

3 ft = 1 yd

= 51.6 ft

1= 51.6 ft

Unit Conversion

Your Turn: Convert 4 feet to inches

4 ft

1X

12 in.1 ft

12 in. = 1 ft

= 48 in.

1= 48 in.

Unit Conversion

4 blocks = 1 inch in length

What is the conversion factor to convert inches to blocks?

4 blocks1 in.

• 6 in. = __________________blocks

• 2 ½ in. = __________________blocks

• 4 ¾ in. = __________________blocks

More Unit Conversions

Your Turn

6 in. ×4 blocks

1 in.= 24

2.5 in. ×4 blocks

1 in.= 10

4.75 in. ×4 blocks

1 in.= 19

Common Conversions

The Gateway Formula Sheet provides many different

length equivalencies.

We can use these to

create conversion

factors.

Common Conversions

What conversion factor would you use to convert

7 feet to a measurement in meters?

1 m

3.28 ft

Desired Unit

Given Unit

7 ft ×1 m

3.28 ft= 2.13 m

Convert 7 feet to meters

Common Conversions

What conversion factor would you use to convert

19 inches to a measurement in centimeters?

2.54 cm

1 in.

Desired Unit

Given Unit

19 in. ×2.54 cm

1 in.= 48.26 cm

Convert 19 in. to cm

Common Conversions

What conversion factor would you use to convert

4 yards to a measurement in meters?

12 ft ×1m

3.28 ft= 3.66 m

Next, convert feet to meters

First, convert yards to feet

4 yd ×3 ft1 yd

= 12 ft

4 yd = 3.66 m

=3 ft1

×12 in.1 ft

+ 5 in.

Example: Convert 3′-5″ to inches

3 ft + 5 in.

12 in. = 1 ft

= 36 in.

1+ 5 in.

= 41 in.

Unit Conversion

Let’s Practice

You used a meter stick to measure your window for new shades. However, the shade packages list the measurements in English units. Luckily your cell phone has a calculator so that you can quickly convert your 81.3 cm by 91.4 cm window opening to English units. What size is your window using English units? Round to the nearest inch.

Let’s PracticeConvert 81.3 cm x 91.4 cm to English

units. Round to the nearest inch.

Therefore, the window opening is 32 in. x 36 in.

81.3 cm ×1 in.

2.54 cm= 32 in.

91.4 cm ×1 in.

2.54 cm= 36 in.

Image Resources

Microsoft, Inc. (2008). Clip Art. Retrieved October 7, 2008, from

http://office.microsoft.com/en-us/clipart/default.aspx