1. Science Skills: Variables For the first 4 problems indicate the independent variable and dependent variable. Follow the directions for Problem 5 as given. Write your answers on a sheet of loose-leaf paper. This is your exit pass for today!

2. A variable is something that can vary or change. What are the variables in this statement? This sample problem will give you the answer in the next slide. The time it takes to run a 10 km race depends on the amount of training the runner does.

3. The independent variable is the amount of training the runner does. The dependent variable is the time it takes the runner to run a 10 km race. It is not enough to say just “time” or “training” – you must describe the I.V. and tell how the D.V. is measured.

4. What are the variables in this statement? Problem 1: The temperature of water is measured at different depths in a lake Independent variable: Dependent variable:

5. What are the variables in this statement? Problem 2: The more water a plant gets, the taller it will grow. Independent variable: Dependent variable:

6. What are the variables in this statement? Problem 3: The number of puppies in a litter is determined by the weight of the mother dog. Independent variable: Dependent variable:

7. What are the variables in this statement? Problem 4: The Texas A & M Extension Service has been counting the number of coyotes in Bexar County. Will the number of coyotes have any effect on the rabbit population? Independent variable: Dependent variable:

8. Problem 5: Lemon trees receiving the most water produce the largest lemons. a. Create a problem question: b. Identify the independent variable: c. Identify the dependent variable: d. List 2 possible constants: e. Explain what you might use for a control.

9. What are the variables in this statement? Problem 1: The temperature of water is measured at different depths in a lake Independent variable: The different depths in the lake at which the water was measured Dependent variable: The temperature of the water at those different depths

10. What are the variables in this statement? Problem 2: The more water a plant gets, the taller it will grow. Independent variable: The amount of water each plant receives Dependent variable: The height to which each plant grows

11. What are the variables in this statement? Problem 3: The number of puppies in a litter is determined by the weight of the mother dog. Independent variable: The weight of the mother dog Dependent variable: The number of puppies in her litter

12. What are the variables in this statement? Problem 4: The Texas A & M Extension Service has been counting the number of coyotes in Bexar County. Will the number of coyotes have any effect on the rabbit population? Independent variable: The number of coyotes in Bexar County Dependent variable: The number of rabbits in Bexar County

13. Problem 5: Lemon trees receiving the most water produce the largest lemons. a. Create a problem question: How much water is ideal to produce the largest lemons? (others can be acceptable) b. Identify the independent variable: The amount of water each lemon tree receives c. Identify the dependent variable: The size of the lemons produced d. List 2 possible constants: type of tree, location, amount of light, soil e. Explain what you might use for a control: A lemon tree grown under normal conditions, no extra water added