1. Length
Units of Measure

2. The Metric System
We are the only major country who is not using the metric system as our primary system of measurement.
We use the English system:
Inches
Feet
Yards
Gallons
Miles

3. The Metric System This puts us at a disadvantage. Why…?
Well, our system of measurement doesn’t really have a “base.”

4. The Metric System There are 12 inches in 1 foot.
There are 3 feet in 1 yard.
There are 5280 feet in 1 mile.
So we have a lot of memorizing to do!

5. The Metric System The metric system, however, is a base 10 system.
There are 10 millimeters in 1 centimeter.
There are 10 centimeters in 1 decimeters.
There are 10 decimeters in 1 meter.
There are 1000 meters in a kilometer.
And so on…

6. The Metric System
So if the metric system is so easy, why doesn’t the United States use it?
Consider the following example…
How do we measure length for our roadways?
Think of the cost to change all of the road signs, mile markers, etc. from english to metric.

7. Metric Prefixes

8. Length The most common tool used to measure length is the ruler.
Most rulers have both english and metric sides.
In this class, we will be using metric measurements.

9. Measuring Length
Using a ruler, line up the zero mark with the beginning of the object that you wish to measure.
Find where the object ends and read the value.
Be sure to always use units.

10. What is the length of the line in centimeters? _______cm
What is the length of the line in millimeters? _______mm
What is the length of the line to the nearest centimeter? ________cm
HINT: Round to the nearest centimeter – no decimals.

11. Length Lab
Follow all instructions on the Length Lab worksheet in order to complete it accurately.