Slide 1: Dependent and Independent
Variables Explained Did you know that if you can add 1+1 then you can learn today’s lesson about variables? : Did you know that if you can add 1+1 then you can learn today’s lesson about variables? Ok…here it goes! 1+1= 2 So, I guess you’re ready! You’re right! It Depends… : You’re right! It Depends… 2 + ____ =__?__ What does this problem equal? Slide 4: 2+2=4 2+4=6 2+50=52 Slide 5: In every example, we changed one number… …and it affected the answer! Therefore, the answer depended on the number we changed! Simple, but try it! : Simple, but try it! Fill in the above problems to make 3 true math sentences. What does this have to do with Science? : What does this have to do with Science? You ask… ? ? ? ? ? ? ? ? Variables are used in Math and Science! : Variables are used in Math and Science! A variable is… something that can be changed. In our math problems, the numbers we changed were called variables. 2+2=4 A constant is… something that does not change. In our math problems, the number we decided not to change could be called a constant. Science experiments use… : Science experiments use… Independent variables – the one factor
changed by the person doing the
experiment. Dependent variables – the factor being
measured in an experiment. Constants – all the factors that stay the
same in an experiment. Slide 10: In our math problems we used independent and dependent variables too! 2+2=4 Constant (It stayed the same) Independent variable (The one number we changed) Dependent variable (The number that depended
on the independent variable) Now, how does it fit with science experiments? : Now, how does it fit with science experiments? Imagine you want to do an experiment to test what kind of plant food works the best. Miracle Gro, Jobe sticks, or the name brand. You would want to be sure that you changed ONLY what you are testing so that your results wouldn’t be messed up. Slide 12: Our Experiment Constants water water water
soil soil soil
light light light
daisy seed daisy seed daisy seed Independent
Variable Miracle Gro Jobe’s Sticks name brand Dependent
Variable Plant growth Plant growth Plant growth
(most) (some) ( very little) A B C Slide 13: Our Constants
and Variables! Constants: The type and amount of dirt (same). The amount and timing of watering (same). The type and amount of light (same). Independent variable: The brand of plant food testing.
(Miracle Gro, Jobes Stick,
name brand) The amount of plant food given (same). Dependent variable: The health and growth of
the plants. + = Slide 14: Same types and amounts of:
water, light, and soil + Different plant foods tested. = Health and
of plants Constants Independent Dependent
Variable Variable Here’s How it Works! Slide 15: for any experiment, you should be able to identify the constants, independent variables, and dependent variables just by thinking… Now... 1+1=2 OR Constants + Independent Var. = Dependent Var. Slide 16: 1.) A student’s grade depends on how much she studies.
2.) The height of a plant and the amount you water it.
Dependent variable: ____________ Slide 17: 3. The amount of money you make and the number of hours you work.
Dependent variable: ____________
4. The number of sodas you buy and the total money spent.
Dependent variable: ____________ Slide 18: 5. The number of houses you can paint depends on how much time you have.
Dependent variable: ____________