Activity 3.2 US Customary Units
Introduction
The United States is the only developed country that does not use the International System of Units. The U
S Customary units are the accepted units of measure. However, due to the global nature of the economy,
SI units are also common. In order to participate in the global market, we must be able to understand and
communicate using various measurement systems.
Procedure
Record the length of each rectangle in fraction form.
Distance
1.
A
2.
B
3.
C
4.
D
5.
E
Measurement (Fraction)
Measurement (Decimal)
6. What is the difference in length between rectangles A and C?
7. What is the difference in length between rectangles B and E?
Using a ruler displaying U S Customary units, measure the missing lengths in the figure below.
Radius of
circle?
Radius of
circle
8. Measure and record the length of additional items in your classroom using a ruler or dial caliper.
Object
Description of
measurement
Pen or
pencil
Thickness
Table
Thickness
Cell Phone
Screen
Length
Keyboard
key
length
Space bar
Length
Object in
your
backpack
____?____
Length
Measurement
9. In your notes or on a isometric paper, create the following diagram. Pay attention to the
measurements.
Conclusion
1. When you look at a drawing, how do you know if you are looking at U S Customary or SI
measurements? Why is it important for an engineer to know this piece of information?
2. What do you feel more comfortable working with SI Unit or US Customary Unit System?
3. What would be your argument to get the United States to change to the SI Unit System?
4. If you were going to design a building which system would you use? Why?
5. If you were going to design a new USB, what system would you use? Why?
6. On a scale of 1 to 5 (Five being really comfortable), how comfortable are you working with a dial
caliper?
7. Provide 3 facts or fun facts about the US Customary System