1. Measurement & Precision
Middle School
Measurement & Precision
Teacher Lesson Guide Presentation
1. Review Theory
Measurements
Measurements help us describe the world and everything in it.
Measurements can describe length, volume, weight, time, temperature, and countless other properties.
Standardized Unit System
Metric system and the English system
Starts 5:50 pm
All content © 2012 FLATE. This material is based upon work supported by the National Science Foundation (NSF) under Grant No Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the NSF.

2. Measurement & Precision
Middle School
Measurement & Precision
Teacher Lesson Guide Presentation
Review Theory, Cont.
Property
Metric Units
English Units
Length
Meters, kilometers
Inch, foot, mile
Volume
cubic centimeters
cubic inches
Fluid Volume
Milliliter, liter
Quart, gallon
Mass
Milligram, gram, kilogram
Ounce, pound, ton
Temperature
degree Celsius (˚C)
degree Fahrenheit (˚F)

3. Measurement & Precision
Middle School
Measurement & Precision
Teacher Lesson Guide Presentation
Review Theory, Cont.
Accuracy
Degree of closeness of measurements results to the true value
Precision, reproducibility or repeatability
The degree to which repeated measurements of a quantity under unchanged conditions show the same results

4. Measurement & Precision
Middle School
Measurement & Precision
Teacher Lesson Guide Presentation
Review Theory, Cont.
Accuracy & Precision Examples
High Precision - Low Accuracy
High Accuracy - Low Precision
True Value
2a. Bell work: Grapic explanation of accuracy and precision. The true value in the center big circle.

5. Measurement & Precision
Middle School
Measurement & Precision
Teacher Lesson Guide Presentation
1a. Exercise
How accurate & Precise are U?
Draw a target and practice accuracy and precision with students, use sticky balls..it will be fun!

6. Measurement & Precision 1b. Tolerance Interval / Margin Error
Middle School
Measurement & Precision
Teacher Lesson Guide Presentation
1b. Tolerance Interval / Margin Error
Example:
Let’s measure Flater using a ruler:
Ruler’s precision:  1/16 (0.063 un)
Tolerance interval: ± un
Hi, My name is Flater!
Explain students the concept of tolerance interval & margin error. Use FLATER as example.

7. Measurement & Precision
Middle School
Measurement & Precision
Teacher Lesson Guide Presentation
2a. Measuring Tools & Their use
Figure 3. Caliper
Figure 1. Ruler
Figure 2. Flexible measuring tape
Students Brainstorm: Show some examples of measuring tools. Have students brain storm and ask students to provide examples of measurement tools and their applications
Figure 4. Long distance measuring tape

8. Measurement & Precision
Middle School
Measurement & Precision
Teacher Lesson Guide Presentation
Sample of Measuring Tools Cont.
More examples…Show measuring tools available in your classroom
Graduated cylinder, measuring cup, water velocity-meter, thermometer, analytical balance

9. Measurement & Precision
Middle School
Measurement & Precision
Teacher Lesson Guide Presentation
Measuring Tools
Calibration
Measuring devices should be calibrated against standards
Example: A set of metric gauge blocks

10. Measurement & Precision
Middle School
Measurement & Precision
Teacher Lesson Guide Presentation
2b. Exercise: Measuring Tools & Units
Which measuring tool and units you will use to measure:
1. Classroom
2. Desk
3. Pencil
Based in the measuring tools you just showed, ask students to identify which measuring tools and units will be more appropriate to measure the length of a classroom, desk, pencil…use more examples as necessary.

11. Measurement & Precision
Middle School
Measurement & Precision
Teacher Lesson Guide Presentation .
3. U Measure it
See exercise: “U Measure it” provided in the handout
a) Use paper ruler (fig.1) & Surgical blade (fig. 5) and provide the following dimensions:
Total and 1/2 of the surgical blade length
The widest part of the blade
The separation between teeth
b) Use a normal ruler (or any other more precise measuring tool) and measure the same points described in (a).
(10 min) Starts 6:00pm Ends 6:10 pm. Make groups of 5 participants!
Have regular & precise rulers, pencil, extra paper, Flaters, ready!

12. Measurement & Precision
Middle School
Measurement & Precision
Teacher Lesson Guide Presentation
3. U Measure it Cont.
c) Compare results from (a: paper ruler) and (b: accurate ruler) in terms of accuracy and precision
Table 2. Measurements of Surgical Blade
Group
No.
Total Height (inches)
½ Height (inches)
Widest part (inches)
Separation between teeth (inches)
Paper ruler
Normal ruler 1 2 3 4 5

13. Measurement & Precision
Middle School
Measurement & Precision
Teacher Lesson Guide Presentation
U Measure it Cont.
d) Report at least the one dimension of the surgical blade in exercise
b) using 3 significant figures and the respective tolerance interval.
Example:
2.3 ±0.05 cm or from 2.25 cm to 2.35 cm. 
c) Explain the range of "tolerance”
e) Explain why the selection of appropriate measurement tools is important in data calculation, design and manufacturing process.
(10 min.) Starts at 6:0pm ends 6:10pm

14. Measurement & Precision
Middle School
Measurement & Precision
Teacher Lesson Guide Presentation
Exercise 4. Zero Waste - U Design it
Use the surgical blade (fig. 5) and the provided sheet of paper (8 ½x11”).
a) What are the steps you would need to take if you were designing and manufacturing surgical blades as shown in the picture?
b) How many surgical blades can you manufacture from a sheet of paper (8 ½x11”). Consider minimum waste of material and maximum product.
c) Draw the possible options for manufacturing the surgical blade and demonstrate the most efficient-zero waste distribution design.
Answers:
a) Required significant figures, thickness of blade, type of material, etc.
Manufacturing: How many surgical blades can you manufacture from a sheet of paper (8 ½ x11”). Consider minimum waste of material and maximum product production.
b) Ask students to outline or draw the possible options for manufacturing the surgical blade and demonstrate the most efficient distribution design with minimum waste and maximum product production.
Option 1: 18 units, option 2: 19 units (option 1, place blade in vertical position, perpendicular to the bottom with of paper, see figure 6. Option 2, place blade in horizontal position, parallel to the bottom with of the paper- see figure 7).
Figure 5

15. Measurement & Precision
Middle School
Measurement & Precision
Teacher Lesson Guide Presentation
Answers. Zero Waste - U Design it
11 blades in horizontal position
The most efficient-zero waste distribution design:
Total19 units
8 blades vertical blades
Answer for the most efficient-zero waste distribution