**Lesson Plan: Percentage Error**
**Class: Senior Secondary 2**
**Subject: Mathematics**
**Duration: 1 Hour**
**Topic: Percentage Error**
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**Learning Objectives:**
By the end of this lesson, students should be able to:
1. Define percentage error.
2. Understand the formula to calculate percentage error.
3. Calculate the percentage error for given data sets.
4. Interpret the significance of percentage error in practical applications.
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**Materials Needed:**
- Whiteboard and markers
- Calculator
- Handouts with example problems
- Graph paper
- Projector (if available)
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**Lesson Outline:**
1. **Introduction (5 minutes)**
- Begin with a brief discussion on measurement and its importance in various fields.
- Highlight situations where measurements are prone to errors.
2. **Lesson Development (10 minutes)**
- **Definition:**
- Define Percentage Error: The amount by which an observed or calculated value deviates from the true value, expressed as a percentage of the true value.
- **Formula:**
- Explain the formula:
\[
\text{Percentage Error} = \left( \frac{|\text{Experimental Value} - \text{Theoretical Value}|}{\text{Theoretical Value}} \right) \times 100
\]
3. **Worked Examples (15 minutes)**
- Present a few worked examples on the board.
- Example 1: If the theoretical value is 50 and the experimental value is 45, calculate the percentage error.
- Solution:
\[
\text{Percentage Error} = \left( \frac{|45 - 50|}{50} \right) \times 100 = 10\%
\]
- Example 2: If the theoretical value is 80 and the experimental value is 76, calculate the percentage error.
- Solution:
\[
\text{Percentage Error} = \left( \frac{|76 - 80|}{80} \right) \times 100 = 5\%
\]
4. **Guided Practice (15 minutes)**
- Divide students into pairs and hand out practice worksheets.
- Instruct students to solve a set of problems, using the formula for percentage error.
- Walk around to provide help and feedback as necessary.
5. **Class Discussion and Summarization (10 minutes)**
- Discuss the answers to the worksheet, confirming the correct solutions.
- Summarize the key points of the lesson.
- Highlight how percentage error is used in various applications like science experiments, quality control in manufacturing, etc.
6. **Independent Practice (5 minutes)**
- Assign a few problems to be done independently as homework.
- Encourage students to report their findings by identifying possible sources of error in each case and interpreting the results.
7. **Conclusion (5 minutes)**
- Ask students to reflect on what they learned about percentage error.
- Provide a preview of the next lesson topic.
- Inform students if there are any upcoming quizzes or assignments related to the topic.
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**Homework:**
1. Calculate the percentage error in the following cases:
- Theoretical value: 100, Experimental value: 93
- Theoretical value: 250, Experimental value: 240
2. Write a brief paragraph on the importance of understanding percentage error in real-life scenarios.
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**Assessment:**
- Participation and engagement during class activities.
- Accuracy in solving guided practice problems.
- Homework completion and accuracy.
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**Notes:**
- Remind students that understanding percentage error is critical in evaluating the precision and accuracy of their results in various experiments and measurements.
- Encourage them to think about how reducing percentage error can lead to better outcomes in real-world applications.