Unit 16: Whole-Number Arithmetic Fluency

Day 6 of 30

Subtract 3-4 digit numbers with regrouping

3-5Mathematics

Content is AI-assisted and continuously improved through educator review

Learning Objective

Students will be able to subtract 3-4 digit numbers with regrouping.

Today's Lesson

In this lesson, we'll explore how to subtract 3-4 digit numbers with regrouping. Mathematical thinking develops logical reasoning and problem-solving abilities.

Regrouping (also called carrying or borrowing) means exchanging one place value for another when adding or subtracting. When adding: If a column sum is 10 or more, regroup by moving the extra to the next column (e.g., 15 ones = 1 ten and 5 ones). When subtracting: If you don't have enough in a place, borrow from the next column (e.g., 1 ten = 10 ones). Regrouping lets you add and subtract any numbers!

As you work through today's material, pay attention to the examples and try to identify the patterns or strategies being used. This will help you apply these concepts to new problems.

Take notes on key points and make connections to what you've already learned in previous lessons.

Key Terms
Problem

A mathematical question requiring analysis and solution

Solution

The result obtained by solving a problem

Activities
Instructions
1. Review the example problems for subtract 3-4 digit numbers with regrouping. 2. Identify the steps and strategies used. 3. Work through practice problems independently. 4. Compare solutions with a partner.
Materials Needed
  • Notebook
  • Calculator (if needed)
  • Graph paper
Practice Problems
1

Add with regrouping: 47 + 36

Hint: 7 + 6 = 13. Write 3, carry 1 to tens.
2

Subtract with regrouping: 52 - 28

Hint: Can't take 8 from 2. Borrow from tens: 12 - 8 = 4.
3

Solve: 245 + 387

Hint: Regroup ones, then tens if needed.

Teaching Tip

For this age group: Balance direct instruction with collaborative activities. Allow students to explain their thinking and make connections to prior knowledge when exploring subtract 3-4 digit numbers with regrouping.

AI Tutor

Get instant help with this lesson. Ask questions and receive personalized explanations from your AI tutor.