Worksheet for identifying independent and dependent variables in scientific experiments.

Problem Analysis:

The task involves identifying independent variables and dependent variables in various scenarios. An independent variable is the one that is manipulated or changed to observe its effect, while a dependent variable is the outcome or result that changes in response to the independent variable.

Let's solve each part of the problem step by step.

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Part 1: Matching Independent and Dependent Variables

We are given pairs of variables and need to identify which is the independent variable (IV) and which is the dependent variable (DV).

#### Scenario 1:
- Independent Variable (IV): The number of pencils purchased.
- Dependent Variable (DV): The total cost of pencils bought.

Explanation: The number of pencils purchased is what you control or change, and the total cost depends on how many pencils you buy.

#### Scenario 2:
- Independent Variable (IV): The grade made on a math test.
- Dependent Variable (DV): The number of questions answered correctly.

Explanation: The grade on a math test is determined by the number of questions answered correctly, so the number of questions answered correctly is the independent variable, and the grade is the dependent variable.

#### Scenario 3:
- Independent Variable (IV): The amount of gasoline used.
- Dependent Variable (DV): The number of miles the car is driven.

Explanation: The amount of gasoline used depends on how many miles the car is driven, so the number of miles driven is the independent variable, and the amount of gasoline used is the dependent variable.

#### Scenario 4:
- Independent Variable (IV): The weight of a puppy.
- Dependent Variable (DV): The age of the puppy.

Explanation: The age of the puppy is what changes over time, and the weight of the puppy depends on its age. Therefore, the age is the independent variable, and the weight is the dependent variable.

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Part 2: Identifying Independent and Dependent Variables in Real-Life Scenarios

We are given several real-life scenarios and need to identify the independent and dependent variables.

#### Scenario 1:
- Statement: The weight of a water balloon with several rocks weighs more than a water balloon with just a few rocks.
- Dependent Variable (DV): The weight of the water balloon.
- Independent Variable (IV): The number of rocks.

Explanation: The weight of the water balloon depends on how many rocks are added, so the number of rocks is the independent variable, and the weight is the dependent variable.

#### Scenario 2:
- Statement: The car wreck was very large, so many emergency workers were there.
- Dependent Variable (DV): The number of emergency workers.
- Independent Variable (IV): The size of the car wreck.

Explanation: The number of emergency workers depends on the size of the car wreck, so the size of the car wreck is the independent variable, and the number of emergency workers is the dependent variable.

#### Scenario 3:
- Statement: The structure of ant colonies depends on the size of the colony.
- Dependent Variable (DV): The structure of ant colonies.
- Independent Variable (IV): The size of the colony.

Explanation: The structure of ant colonies changes based on the size of the colony, so the size of the colony is the independent variable, and the structure is the dependent variable.

#### Scenario 4:
- Statement: The temperature of the ice tea dropped each minute.
- Dependent Variable (DV): The temperature of the ice tea.
- Independent Variable (IV): The amount of time it was in the fridge.

Explanation: The temperature of the ice tea depends on how long it has been in the fridge, so the amount of time is the independent variable, and the temperature is the dependent variable.

#### Scenario 5:
- Statement: The tall of the bowling ball was high because several people attended the bowling party.
- Dependent Variable (DV): The height of the bowling ball.
- Independent Variable (IV): The number of people who attended.

Explanation: The height of the bowling ball depends on the number of people attending the bowling party, so the number of people is the independent variable, and the height is the dependent variable.

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Final Answer:

\[
\boxed{
\begin{array}{l}
\text{Part 1:} \\
1. \text{IV: Number of pencils purchased, DV: Total cost of pencils bought.} \\
2. \text{IV: Number of questions answered correctly, DV: Grade made on a math test.} \\
3. \text{IV: Number of miles the car is driven, DV: Amount of gasoline used.} \\
4. \text{IV: Age of the puppy, DV: Weight of the puppy.} \\
\\
\text{Part 2:} \\
1. \text{DV: Weight of the water balloon, IV: Number of rocks.} \\
2. \text{DV: Number of emergency workers, IV: Size of the car wreck.} \\
3. \text{DV: Structure of ant colonies, IV: Size of the colony.} \\
4. \text{DV: Temperature of the ice tea, IV: Amount of time in the fridge.} \\
5. \text{DV: Height of the bowling ball, IV: Number of people who attended.}
\end{array}
}
\]