1. Review of Scientific Variables

2. Review of Scientific Variables
Identify the variables in each of the following examples.
A scientist was trying to see if the amount of water a plant gets affects plant growth. She collected 10 identical plants and gave them different amounts of water. She measured their growth daily. The plants received the same amount of sunlight.
What is the manipulated variable in the above investigation?
Plant growth
Amount of sunlight
Amount of water
10 plants

3. Review of Scientific Variables
Identify the variables in each of the following examples.
A scientist was trying to see if the amount of water a plant gets affects plant growth. She collected 10 identical plants and gave them different amounts of water. She measured their growth daily. The plants received the same amount of sunlight.
2. What is the responding variable?
Amount of sunlight
Plant growth
Growth measured daily
The method used to measure the plants

4. Review of Scientific Variables
Identify the variables in each of the following examples.
A scientist was trying to see if the amount of water a plant gets affects plant growth. She collected 10 identical plants and gave them different amounts of water. She measured their growth daily. The plants received the same amount of sunlight.
3. What are the controlled variables?
Amount of sunlight
10 identical plants
Amount of water
Both A and B

5. Review of Scientific Variables
Identify the manipulated and responding variable(s) in each question from the information given. Then, think of at least two controlled variables that could be set for each experiment.
4. Does the shape of a container affect how fast water will evaporate form it?
Shape of container
Manipulated variable: __________________________
Responding variable: __________________________
Controlled variable 1: __________________________
Controlled variable 2: __________________________
Rate of evaporation
Volume / temperature of water
Time measurement is taken

6. Review of Scientific Variables
Identify the manipulated and responding variable(s) in each question from the information given. Then, think of at least two controlled variables that could be set for each experiment.
5. How does the distance from a flashlight to a screen affect the size of the illuminated area?
Distance of flashlight to screen
Manipulated variable: __________________________
Responding variable: __________________________
Controlled variable 1: __________________________
Controlled variable 2: __________________________
Size of illuminated area
Same flashlight for each distance
Same method of measuring area

7. Review of Scientific Variables
Identify the manipulated and responding variable(s) in each question from the information given. Then, think of at least two controlled variables that could be set for each experiment.
6. How does the weight of a parachute load affect how fast it will fall?
Weight of parachute load
Manipulated variable: __________________________
Responding variable: __________________________
Controlled variable 1: __________________________
Controlled variable 2: __________________________
Rate of fall
Area of open chute
Height at which load was dropped

8. Review of Scientific Variables
Identify the manipulated and responding variable(s) in each question from the information given.
7. Scientists were trying to determine if junk food would cause a mouse to gain weight. The diet of mice was varied. Some mice were given junk food. Others were given Mouse Chow. The mice were weighed daily. All mice were the same sex, the same age, and the same species.
Type of diet
Manipulated variable: __________________________
Responding variable: __________________________
Controlled variable 1: __________________________
Controlled variable 2: __________________________
Weight of mouse measured daily
Same age and species of mouse
Same sex, time of measurement

9. Review of Scientific Variables
Identify the manipulated and responding variable(s) in each question from the information given. Then, think of at least two controlled variables that could be set for each experiment.
8. How does the amount of fertilizer a farmer uses affect the number of beans he harvests?
Amount of fertilizer
Manipulated variable: __________________________
Responding variable: __________________________
Controlled variable 1: __________________________
Controlled variable 2: __________________________
Number of beans harvested
Same amount of water, sunshine
Same type of soil, fertilizer

10. Review of Scientific Variables
Identify the manipulated and responding variable(s) in each question from the information given. Then, think of at least two controlled variables that could be set for each experiment.
9. Do different types of food mold at different rates?
Type of food
Manipulated variable: __________________________
Responding variable: __________________________
Controlled variable 1: __________________________
Controlled variable 2: __________________________
Rate of molding
Exposure to same environment
Time span that molding occurs

11. Review of Scientific Variables
10. A scientist was trying to determine if the shape of hot air balloons would affect how high they went. The shape of 10 hot air balloons varied. Some were oval; some were round. The altitude (how high they went) was measured. The scientist tested them on the same day so the weather conditions would be the same. The balloons had the same air volume.
Shape of balloon
Manipulated variable: __________________________
Responding variable: __________________________
Controlled variable 1: __________________________
Controlled variable 2: __________________________
How high the balloons would go
Method of measurement; same day
Balloons were same volume

12. Review of Scientific Variables
11. Study the chart below. Identify the manipulated, responding, and controlled variables.
Sugar Sample
Water Conditions
Time to Dissolve (min)
Whole sugar cube
Hot 5
Two-half sugar cubes 3
Crushed sugar cube
hot 1
Surface area of sugar sample
Manipulated variable: __________________________
Responding variable: __________________________
Controlled variable 1: __________________________
Controlled variable 2: __________________________
Time to dissolve
Same temperature of water
Same size container for sugar and water