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

# Grade 3 Mathematics Lesson Plan ## Topic: Addition and Subtraction (Three-Digit Numbers) ### Duration: 60 minutes --- ### Objectives: - Students will understand and apply addition and subtraction of three-digit numbers. - Students will use strategies such as carrying and borrowing (regrouping) effectively. - Students will solve word problems that involve adding and subtracting three-digit numbers. ### Materials Needed: - Whiteboard and markers - Base-ten blocks (or similar manipulatives) - Worksheets with addition and subtraction problems - Number lines - Notebooks and pencils - Flashcards with three-digit addition and subtraction problems - Projector/Interactive whiteboard (for displaying examples) ### Common Core Standards: - CCSS.MATH.CONTENT.3.NBT.A.1: Use place value understanding to round whole numbers to the nearest 10 or 100. - 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. - CCSS.MATH.CONTENT.3.OA.A.3: Solve two-step word problems using addition and subtraction. --- ### Lesson Structure: #### 1. Introduction (10 minutes) - **Greeting and Objective Introduction:** - Greet the class and introduce the topic for the day: Addition and Subtraction of Three-Digit Numbers. - Explain the objectives of the lesson. - Ask introductory questions to gauge students' prior knowledge. - **Warm-Up Activity:** - Have students solve a few basic two-digit addition and subtraction problems on their whiteboards. - Discuss the strategies they used and introduce the concept of moving to three-digit numbers. #### 2. Direct Instruction (15 minutes) - **Addition of Three-Digit Numbers:** - Write a three-digit addition problem on the board (e.g., 456 + 289). - Demonstrate the addition process, emphasizing carrying over when the sum exceeds 9. - Use base-ten blocks or number lines to visually represent the problem. - **Subtraction of Three-Digit Numbers:** - Write a three-digit subtraction problem on the board (e.g., 652 - 374). - Demonstrate the borrowing process when the top digit is smaller than the bottom digit. - Use manipulatives to show how borrowing works. #### 3. Guided Practice (15 minutes) - **Group Activity:** - Divide students into small groups and provide each group with a set of base-ten blocks and worksheets containing addition and subtraction problems. - Guide the groups to solve the problems, ensuring they use the blocks to model carrying and borrowing. - **Interactive Questions:** - Display problems on the projector/interactive whiteboard and have volunteers come up to solve them. - Discuss the steps taken and clarify any misunderstandings. #### 4. Independent Practice (10 minutes) - **Worksheet Completion:** - Hand out worksheets with a mix of addition and subtraction problems. - Encourage students to solve the problems independently in their notebooks. - Walk around the classroom to provide individual support as needed. #### 5. Real-World Application and Word Problems (10 minutes) - **Word Problems:** - Present a few word problems involving three-digit addition and subtraction (e.g., "Sally had 345 apples. She bought 128 more. How many apples does she have now?"). - Work through the first problem as a class, modeling the process of extracting numbers and determining whether to add or subtract. - Allow students to work on additional word problems in pairs or small groups. #### 6. Closing and Review (10 minutes) - **Review Key Points:** - Summarize the key strategies for adding and subtracting three-digit numbers. - Highlight the importance of checking their work by using inverse operations. - **Exit Tickets:** - Provide each student with a flashcard that has a three-digit addition or subtraction problem. - Have students solve the problem and hand it in as they leave to assess their understanding. - **Homework:** - Assign a simple worksheet for additional practice at home or ask students to create their own three-digit problems and solve them. ### Assessment: - Observation during guided practice. - Completion and accuracy of independent practice worksheets. - Correctness of answers on exit tickets. ### Differentiation: - **For Advanced Learners:** - Provide more challenging problems that involve multiple steps or introduce four-digit problems. - **For Struggling Learners:** - Offer one-on-one or small group support, using additional manipulatives and visual aids. ### Reflection: - After the class, reflect on what worked well and what could be improved. Adjust future lessons based on student performance and feedback. --- By carefully following this lesson plan, students will enhance their understanding and skills in adding and subtracting three-digit numbers and be able to apply these skills to real-world problems.