Science worksheet for students to practice identifying dependent, independent, and control variables in experimental scenarios.

Problem: Identifying Variables in Scientific Experiments

The task is to identify the dependent variable, independent variable, and control variable (if applicable) for each scenario described in the worksheet. Below is a detailed explanation and solution for each question.

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1. Two groups of sixth graders were tested to compare their speed in solving long division problems. One group had calculators, the other didn't.

- Dependent Variable: The speed in solving long division problems is the outcome being measured. It depends on whether or not the students used calculators.

- Independent Variable: The use of calculators is the factor being manipulated. One group has calculators, and the other does not.

- Control Variable: The grade level of the students (sixth graders) is a control variable because it ensures that all participants are at the same educational level, minimizing variability due to differences in age or skill.

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2. Students of different grades were given the same jigsaw puzzle to assemble. The time they took to assemble it was measured.

- Dependent Variable: The time taken to assemble the jigsaw puzzle is the outcome being measured. It depends on the grade level of the students.

- Independent Variable: The grade level of the students is the factor being manipulated. Different grades are compared to see how their performance varies.

- Control Variable: The jigsaw puzzle itself is a control variable because it is the same for all students, ensuring that the difficulty of the puzzle does not vary between groups.

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3. Sasha wanted to figure out what type of liquid worked best for growing beans. She watered one with coca-cola, one with lemonade, and one with just water. After one week, she measured how high they had grown.

- Dependent Variable: The height of the beans after one week is the outcome being measured. It depends on the type of liquid used for watering.

- Independent Variable: The type of liquid used for watering (coca-cola, lemonade, or water) is the factor being manipulated.

- Control Variable: The type of bean plant and the amount of liquid given are control variables. These ensure that the growth difference is due to the type of liquid and not other factors like the plant species or the amount of liquid provided.

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4. Miss Kobayashi wanted to find out what fertilizer works best in growing Marigolds. She put Miracle Grow on the first pot of Marigold, then Scotts Fertilizer on the second pot of Marigold, and no fertilizer on the third pot.

- Dependent Variable: The growth of the Marigolds (e.g., height, number of flowers, overall health) is the outcome being measured. It depends on the type of fertilizer used.

- Independent Variable: The type of fertilizer applied (Miracle Grow, Scotts Fertilizer, or no fertilizer) is the factor being manipulated.

- Control Variable: The type of Marigold plant and the amount of sunlight/water are control variables. These ensure that the growth difference is due to the fertilizer and not other factors like the plant species or environmental conditions.

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5. Luffy wanted to see if eating apples would help him do better on his classwork. The first day, he didn’t eat any apples. On the 2nd day, he ate one apple; on the 3rd day, he ate 2 apples; and on the 4th day, he ate 3 apples. Each day, he recorded the grades he got on his science work.

- Dependent Variable: The grades he got on his science work are the outcome being measured. They depend on the number of apples eaten.

- Independent Variable: The number of apples eaten per day (0, 1, 2, or 3) is the factor being manipulated.

- Control Variable: The difficulty of the science work and the time spent studying are control variables. These ensure that the grades are influenced by the number of apples eaten and not by variations in the difficulty of the assignments or study habits.

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Final Answers:

1.
- Dependent Variable: Speed in solving long division problems
- Independent Variable: Use of calculators
- Control Variable: Grade level of students

2.
- Dependent Variable: Time taken to assemble the jigsaw puzzle
- Independent Variable: Grade level of students
- Control Variable: Jigsaw puzzle

3.
- Dependent Variable: Height of beans after one week
- Independent Variable: Type of liquid used for watering
- Control Variable: Type of bean plant, amount of liquid given

4.
- Dependent Variable: Growth of Marigolds
- Independent Variable: Type of fertilizer applied
- Control Variable: Type of Marigold plant, amount of sunlight/water

5.
- Dependent Variable: Grades on science work
- Independent Variable: Number of apples eaten per day
- Control Variable: Difficulty of science work, time spent studying

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Final Answer Box:

\[
\boxed{
\begin{array}{l}
\text{1. Dependent: Speed in solving long division problems} \\
\text{ Independent: Use of calculators} \\
\text{ Control: Grade level of students} \\
\text{2. Dependent: Time taken to assemble the jigsaw puzzle} \\
\text{ Independent: Grade level of students} \\
\text{ Control: Jigsaw puzzle} \\
\text{3. Dependent: Height of beans after one week} \\
\text{ Independent: Type of liquid used for watering} \\
\text{ Control: Type of bean plant, amount of liquid given} \\
\text{4. Dependent: Growth of Marigolds} \\
\text{ Independent: Type of fertilizer applied} \\
\text{ Control: Type of Marigold plant, amount of sunlight/water} \\
\text{5. Dependent: Grades on science work} \\
\text{ Independent: Number of apples eaten per day} \\
\text{ Control: Difficulty of science work, time spent studying} \\
\end{array}
}
\]