Middle School
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
All content © 2012 FLATE. This material is based upon work supported by the National Science Foundation (NSF) under Grant No. 0802436. 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.
1
Middle School
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)
2
Middle School
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
3
Middle School
Teacher Lesson Guide Presentation
Review Theory, Cont.
Accuracy & Precision Examples
High Accuracy - Low Precision
High Precision - Low Accuracy
True Value
4
Middle School
Teacher Lesson Guide Presentation
1a. Exercise
How accurate & Precise are U?
5
Middle School
Teacher Lesson Guide Presentation
1b. Tolerance Interval / Margin Error
Example:
Let’s measure Flater using a ruler:
Hi, My name is
Flater!
Ruler’s precision: 1/16 (0.063 un)
Tolerance interval: 2.25 ± 0.063 un
6
Middle School
Teacher Lesson Guide Presentation
2a. Measuring Tools & Their use
Figure 1. Ruler
Figure 3. Caliper
Figure 2. Flexible measuring tape
Figure 4. Long distance measuring tape
7
Middle School
Teacher Lesson Guide Presentation
Sample of Measuring Tools Cont.
Graduated cylinder, measuring cup, water
velocity-meter, thermometer, analytical balance
8
Middle School
Teacher Lesson Guide Presentation
Measuring Tools
Calibration
Measuring devices should be calibrated against standards
Example: A set of metric gauge blocks
9
Middle School
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
10
Middle School
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).
11
Middle School
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
½ Height
(inches)
(inches)
Paper Normal Paper Normal
ruler
ruler
ruler
ruler
Widest part
(inches)
Paper Normal
ruler
ruler
Separation between
teeth (inches)
1
2
3
4
5
12
Middle School
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.
13
Middle School
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.
Figure 5
14
Middle School
Teacher Lesson Guide Presentation
Answers. Zero Waste - U Design it
The most efficient-zero waste
distribution design:
Total19 units
8 blades vertical blades
11 blades in horizontal position
15