# 15(Aug25) Independent Variables

```Bellwork
SPI 0807.Inq.1
(Variables and Controls)
1. Find the perimeter of an object that
has sides 8cm, 13cm, 8cm, and
13cm.
2. Find the density of a cube if the
mass is 10g and the volume is 60
mL.
3. Find the area of a book that is 12
cm long and 7 cm wide.
4. Find the volume if the length is
8cm, the width is 10cm, and the
height is 7.
5. Find the volume of the person in
the picture.
8/25/2015
Bellwork
SPI 0807.Inq.1
(Variables and Controls)
1. Find the perimeter of an object that
has sides 8cm, 13cm, 8cm, and
13cm. 42cm
2. Find the density of a cube if the
mass is 10 g and the volume is 60
mL. 1/6 g/mL
3. Find the area of a book that is 12
cm long and 7 cm wide. 84 cm2
4. Find the volume if the length is
8cm, the width is 10cm, and the
height is 7. 560cm3
5. Find the volume of the person in
the picture. 1.6mL
8/25/2015
Agenda
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SPI 0807.Inq.1
(Variables and Controls)
8/25/2015
Review Bellwork
Emphasize Today’s Objective
Check definitions
Notes on Independent Variable
Work on measurement worksheet and study
guide
Homework:
Study for quiz
Do measurement worksheet
Notes
SPI 0807.Inq.1
(Variables and Controls)
8/25/2015
1. Independent Variable is the variable you
choose to test or change.
2. Dependent Variable is the variable being
measured or observed in an experiment.
3. Hypothesis is a possible answer to a
question or a solution to a problem.
4. Procedure is the steps that are taken to
solve a problem or answer a question
Notes
SPI 0807.Inq.1
(Variables and Controls)
Science
Analysis is looking at results, data collected for example,
to decide if the question was answered or the problem
solved.
Controlled variable is the variable that is held constant in
an experiment.
Notes
SPI 0807.Inq.1
(Variables and Controls)
Science
Variables and Controls in Experiments
 Used with the scientific method
Scientific Method
(In List Format)
Step 1: Make Observations
Step 3: Form A Hypothesis
Step 4: Test The Hypothesis
 By doing experiments
Step 5: Analyze The Results
Step 6: Draw Conclusions
Step 7: Communicate results
 Use independent variables when you test your hypothesis by
doing experiments (see step 4 above)
Notes
SPI 0807.Inq.1
(Variables and Controls)
Science
Experiments
 In an experiment you should conduct multiple trials
How many? More is better!
 Experiments should include independent variables,
dependent variables, constants, and controls.
Notes
SPI 0807.Inq.1
(Variables and Controls)
Science
Experiments (F.Y.I):
 You test or measure a quantity and/or quality of something.
Example: Measuring Quantity:
Scientists could be testing a new cell
phone battery to determine how long
it will last when you are text
messaging.
Example: Measuring Quality:
Scientists could be testing new IPod
ear buds to determine if they are more
comfortable or not.
Notes
SPI 0807.Inq.1
(Variables and Controls)
Science
Independent Variables
In an experiment…
 …you should only test for ONE key thing at a time
When you repeat the experiment…
 …only change this ONE key thing
This one thing is called…
Also know as….the manipulated variable
Notes
SPI 0807.Inq.1
(Variables and Controls)
Science
Memory Trick
“I”

Independent variable begins with the letter


So remember the letter
Imagine yourself doing the experiment., and ask yourself…
“I.”
“What ONE thing will

I change when repeating the experiment?”
That one thing will be…
Also know as….the manipulated variable
Video
Review
SPI 0807.Inq.1
(Variables and Controls)
Science
 Let's take a moment to watch and
Link: Variables Song by Mr. Edmonds
Example: You decide to do an experiment to determine the reason
certain soft drinks are more popular that others. You suspect that the
popularity of the drinks is connected with the amount of sugar found in
them. You decide to use Dr. Pepper, Coke, Pepsi, and Barq's root beer.
You first determine how much sugar each drink contains.
Then you get 6 students to do a blind taste test with all 4 drinks.
What is the independent (manipulated) variable in this example?
In other words, what is the one thing being tested for or changed?
The independent variable is the type of soft drink
Example: A scientist is conducting an experiment to test how
sunlight affects plant growth.
 She places one corn plant 1 meter away from a sunlamp.
 She places one corn plant 2 meters away from a sunlamp.
 She places one corn plant 3 meters away from a sunlamp.
Corn plant 01
Corn plant 02
Corn plant 03
What is the independent (manipulated) variable in this example?
In other words, what is the one thing being tested for or changed?
The independent variable is the distance from the sunlamp
which is connected with the amount of sunlight.
Example: A student conducts an experiment with ten 8th grade
students. He uses 3 similar types of sour candy in a series of 4
trials. (Sour Patch Kids, Sour Skittles, and Warheads) He gives
1 piece of candy to each student and records their facial expressions
to estimate how sour each candy is.
What is the independent (manipulated) variable in this example?
In other words, what is the one thing being tested for or changed?
The independent variable is the type of sour candy
Example: A student conducts an experiment to determine
which type of glue works best for attaching two pieces of regular
writing paper together.
She places 2g of glue on each sheet of paper and then uses a spring scale
to measure how much force it takes to pull the sheets apart.
She uses 3 types of Elmer’s glue in a series of experiments.
Glue Stick-nonwashable
Liquid-washable
Glue Stick-washable
What is the independent (manipulated) variable in this example?
In other words, what is the one thing being tested for or changed?
The independent variable is the type of glue
Example: A student conducts an experiment to determine which
ink color in ballpoint pens will last the longest before running out.
She copies text from her science book. She copies the same text over and over.
She writes at the same speed. The room temperature remains the same. She
writes on the same kind of paper each time.
She uses 3 ink colors in 3 ballpoint pens in a series of experiments.
(1) Black ink pen,
(2) Blue ink pen,
(3) Red ink pen)
What is the independent (manipulated) variable in this example?
In other words, what is the one thing being tested for or changed?
The independent variable is the color of ink
Questions
SPI 0807.Inq.1A
(Independent Variables)
Science
Here is an example of a question you might see on a quiz or test.
Questions
SPI 0807.Inq.1A
(Independent Variables)
Science
Here is an example of a question you might see on a quiz or test.
Questions
SPI 0807.Inq.1A
(Independent Variables)
Science
Here is an example of a question you might see on a quiz or test.
Questions
SPI 0807.Inq.1A
(Independent Variables)
Science
Here is an example of a question you might see on a quiz or test.
Questions
SPI 0807.Inq.1A
(Independent Variables)
Science
Here is an example of a question you might see on a quiz or test.
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