1. Independent / Dependent Variables
Sept. 3rd, 2009
Independent / Dependent Variables

2. What is a Variable?
A variable is a single letter of the alphabet that represents some unknown value
Once I find out that unknown value, I replace it with the actual number
Examples
# of books on bookself = b
Coach Melm’s Shoesize = s
Amount of money school spends on paper = m

3. b m Your cell phone bill depends on the minutes used.
(variable)
(variable) b m
Your b depends on the m
Which Happens First?
Bill
Minutes
(2nd)
(1st)
1st thing that happens is called the INDEPENDENT VARIABLE
2nd “ “ “ “ “ “ DEPENDENT VARIABLE

4. g s Your 6 week grade depends on how much you studied.
(variable)
(variable) g s
Your g depends on how much you s .
Which Happens First?
Grade
Studied
(2nd)
(1st)
1st thing that happens is called the INDEPENDENT VARIABLE
2nd “ “ “ “ “ “ DEPENDENT VARIABLE

5. s t Your tiredness depends on how much sleep you got.
(variable)
(variable) s t
Your t depends on how much s you got.
Which Happens First?
Tiredness
Sleep
(2nd)
(1st)
1st thing that happens is called the INDEPENDENT VARIABLE
2nd “ “ “ “ “ “ DEPENDENT VARIABLE

6. w p Which Happens First? Winner Points (2nd) (1st)
The winner of a football game depends on who scored more points.
(variable)
(variable) w p
The w depends on who scored more p
Which Happens First?
Winner
Points
(2nd)
(1st)
1st thing that happens is called the INDEPENDENT VARIABLE
2nd “ “ “ “ “ “ DEPENDENT VARIABLE

7. e j Which Happens First? Jobs Education (2nd) (1st)
Opportunities for high paying jobs depend on how much education you have.
(variable)
(variable) e j
Opportunities for j depend on how much e you have.
Which Happens First?
Jobs
Education
(2nd)
(1st)
1st thing that happens is called the INDEPENDENT VARIABLE
2nd “ “ “ “ “ “ DEPENDENT VARIABLE