Lesson Plan for Grade 3 - Mathematics - Addition and Subtraction (three-digit numbers)

**Lesson Plan: Addition and Subtraction (Three-Digit Numbers) for Grade 3** **Objective:** Students will be able to add and subtract three-digit numbers with and without regrouping. **Common Core Standards:** - CCSS.MATH.CONTENT.3.NBT.A.2: Fluently add and subtract within 1000 using strategies and algorithms based on place value, properties of operations, and/or the relationship between addition and subtraction. **Materials:** - Whiteboard and markers - Base-ten blocks - Place value charts - Worksheets with three-digit addition and subtraction problems - Math journals - Pencils and erasers **Lesson Duration:** 60 minutes **Lesson Outline:** 1. **Introduction (10 minutes):** - **Greeting and Objective:** Welcome students and introduce the objective of the lesson: "Today, we will learn how to add and subtract three-digit numbers." - **Review Previous Concepts:** Briefly review the addition and subtraction of two-digit numbers and the concept of place value (hundreds, tens, units). 2. **Direct Instruction (15 minutes):** - **Addition with Regrouping:** - Write an example on the board: 456 + 378. - Explain each step: Start from the rightmost digit (units), add 6 + 8 = 14, write down 4 in the units column and carry over 1 to the tens column. - Continue with the tens column: 5 + 7 = 12, plus the carried over 1 = 13. Write down 3 in the tens column and carry over 1 to the hundreds column. - Proceed with the hundreds column: 4 + 3 = 7, plus the carried over 1 = 8. Write down 8 in the hundreds column. - **Subtraction with Regrouping:** - Write an example on the board: 642 - 389. - Explain each step: Start from the rightmost digit (units), if 2 < 9, borrow 1 from the tens column making it 12 - 9 = 3. - Proceed to the next column: tens column becomes 3 (original 4 minus 1 borrowed) - 8. Since 3 < 8, borrow from the hundreds making it 13 - 8 = 5. - Finally, the hundreds column: 5 (original 6 minus 1 borrowed) - 3 = 2. 3. **Guided Practice (15 minutes):** - Distribute place value charts and base-ten blocks to students. - Guide students through several examples of three-digit addition and subtraction problems using the place value charts and blocks. - Allow students to solve problems in pairs and walk around to offer assistance. 4. **Independent Practice (10 minutes):** - Provide worksheets with three-digit addition and subtraction problems. - Instruct students to complete the worksheet independently. - Monitor progress and provide support as needed. 5. **Closure and Review (5 minutes):** - Review key concepts and steps for addition and subtraction with regrouping. - Ask students to share any strategies they found helpful. - Address any remaining questions. 6. **Assessment and Homework (5 minutes):** - Collect the completed worksheets for assessment. - Assign a few addition and subtraction problems for homework to reinforce the day's lesson. **Differentiation:** - For struggling students: Use more visual aids (like base-ten blocks) and provide one-on-one or small group instruction. - For advanced students: Challenge them with word problems that require addition and subtraction of three-digit numbers or introduce early concepts of four-digit addition and subtraction. **Reflection:** - After the lesson, reflect on what worked well and what could be improved. - Consider student feedback and performance to plan further lessons on this topic or to identify areas that need additional reinforcement. **Extension Activities:** - Introduce simple word problems to apply three-digit addition and subtraction in real-life contexts. - Use educational math games or digital apps that practice addition and subtraction of three-digit numbers for further engagement.