Adding With Regrouping

Objective

Students will understand and accurately perform 3-digit addition with regrouping.

Curriculum Area

California Common Core State Standards for Mathematics (CCSSM): Grade 4 - Number & Operations in Base Ten

• CCSS.MATH.CONTENT.4.NBT.B.4: Fluently add and subtract multi-digit whole numbers using the standard algorithm.

Materials Needed

• Whiteboard and markers
• Paper and pencils
• Set of number cards (0-9)
• Manipulatives (e.g., base-ten blocks)
• Worksheets with 3-digit addition problems

Lesson Plan

Introduction (5 minutes)

1. Warm-Up Activity: Begin with a quick mental math exercise. Ask each student to add a pair of 2-digit numbers mentally. For example:

   • What is 34 + 58?
   • What is 46 + 29?

2. Purpose: Explain that today they will learn how to add 3-digit numbers with regrouping, which involves carrying over numbers. Explain the importance of accurate addition skills in everyday life.

Direct Instruction (10 minutes)

1. Review of Place Value (2 minutes):

   • Quickly review the place value of hundreds, tens, and ones. Use the base-ten blocks if needed.
   • Explain how regrouping involves shifting values from one column to the next when sums exceed 9.

2. Demonstration with Examples (8 minutes):

   • Write an example problem on the whiteboard such as 247 + 368.
   • Solve it step by step:
     1. Add the ones place: (7 + 8 = 15). Write 5 in the ones place and carry over 1 to the tens place.
     2. Add the tens place: (4 + 6 = 10) plus the 1 carried over gives 11. Write 1 in the tens place and carry over 1 to the hundreds place.
     3. Add the hundreds place: (2 + 3 = 5) plus the 1 carried over gives 6.
     4. Therefore, (247 + 368 = 615).

3. Guided Practice:

   • Write another problem (e.g., 432 + 279) and solve it together with students using similar steps. Encourage students to use base-ten blocks to visualize the regrouping process.

Practice (12 minutes)

1. Collaborative Practice (6 minutes):

   • Provide each student with a paper and a set of number cards. Ask them to draw 3 cards to form a random 3-digit number.
   • Pair the students to work together to add their numbers. Ensure they verbalize the regrouping process.

2. Individual Practice (6 minutes):

   • Hand out the worksheet with more 3-digit addition problems for each student.
   • Monitor and provide individual assistance as needed. Emphasize the steps of checking their work to ensure accuracy.

Assessment & Closure (8 minutes)

1. Assessment:

   • Collect and review the worksheets to assess their understanding.
   • As they finish their worksheets, have students check their answers with a partner.

2. Closure Discussion:

   • Ask each student to share one tip or trick they learned that helps them remember how to regroup.
   • Discuss any challenges and how they overcame them.

3. Homework Assignment:

   • Assign a few 3-digit addition problems for homework. Encourage students to teach a family member the regrouping concept.

Reflection

End the class by gathering feedback:

• What did they enjoy about the lesson?
• Was there a part they found particularly challenging?

Tailor future lessons based on their input to make the learning process more effective and engaging.