### Lesson Plan: Addition and Subtraction (Three-Digit Numbers)
#### Grade Level: Year 3
#### Subject: Mathematics
#### Topic: Addition and Subtraction with Three-Digit Numbers
#### Duration: 60 minutes
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#### Learning Objectives:
- Students will understand the concept of adding and subtracting three-digit numbers.
- Students will be able to solve addition and subtraction problems involving three-digit numbers.
- Students will demonstrate an ability to use place value knowledge in performing operations.
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#### Materials Needed:
- Whiteboard and markers
- Chart paper or large paper for demonstration
- Mini whiteboards for students or math notebooks
- Manipulatives (e.g., base-ten blocks)
- Worksheets with three-digit addition and subtraction problems
- Pencils and erasers
- Calculators (optional, for checking work)
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#### Introduction (10 minutes):
1. **Review Previous Knowledge**: Begin with a brief review of place value concepts (hundreds, tens, and units) and basic addition and subtraction without regrouping.
2. **Introduction to the Lesson**: Explain to students that today, they will be learning how to add and subtract three-digit numbers. Write a sample three-digit addition and subtraction problem on the board and discuss in simple terms.
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#### Instruction (20 minutes):
1. **Addition Demonstration**:
- Write a sample problem on the board: 243 + 176.
- Demonstrate step-by-step:
- Add the units place: 3 + 6 = 9.
- Add the tens place: 4 + 7 = 11 (write down 1 and carry over 1 to the hundreds place).
- Add the hundreds place with the carried-over 1: 2 + 1 + 1 = 4.
- Write the answer: 243 + 176 = 419.
2. **Subtraction Demonstration**:
- Write a sample problem on the board: 572 - 348.
- Demonstrate step-by-step:
- Subtract the units place: 2 - 8 (since 2 < 8, we need to borrow 1 from the tens place, making it 12 - 8 = 4).
- Modify the tens place and subtract: 6 - 4 = 2 (since we borrowed 1).
- Subtract the hundreds place: 5 - 3 = 2.
- Write the answer: 572 - 348 = 224.
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#### Guided Practice (15 minutes):
1. **Group Activity**: Divide students into small groups and provide each group with sample problems to solve together using manipulatives like base-ten blocks. Circulate among the groups to provide assistance and ensure understanding.
2. **Class Discussion**: Reconvene as a class and select a few groups to share their solutions on the board. Discuss any discrepancies and correct misunderstandings together.
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#### Independent Practice (10 minutes):
1. **Worksheet**: Distribute a worksheet with a series of three-digit addition and subtraction problems. Ensure a mix of problems with and without regrouping.
2. **Monitoring**: Walk around the classroom to assist students individually and check for comprehension. Provide timely feedback and encouragement.
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#### Closure (5 minutes):
1. **Review and Reflect**: Summarize the key steps for addition and subtraction of three-digit numbers. Emphasize the importance of checking work and using place value correctly.
2. **Exit Ticket**: Ask students to solve one addition and one subtraction problem on a piece of paper. Collect these as they leave the classroom to assess understanding.
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#### Assessment:
- Formative assessment through observation during the lesson and by reviewing group and individual work.
- Conference with students who need additional support based on their exit tickets and worksheet performance.
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#### Homework:
- Assign a set of three-digit addition and subtraction problems for practice at home. Include a mix of problems to reinforce the day's learning.
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#### Differentiation:
- **Support**: Pair struggling students with peers who can assist them, provide step-by-step guides, and utilize manipulatives.
- **Challenge**: Provide advanced students with word problems or larger numbers for more complex addition and subtraction practice.
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This lesson plan aims to build a robust understanding of three-digit addition and subtraction, ensuring that students can confidently apply these skills to solve arithmetic problems.