MathIsimple
Back to Unit 1
Lesson 1-3
Two-Digit Operations

Two-Digit Subtraction Without Regrouping

Master two-digit subtraction without regrouping through interactive activities, visual models, and real-world scenarios like grocery shopping and inventory management.

Learning Objectives

  • Subtract two-digit numbers without regrouping using multiple strategies
  • Use number lines to visualize and solve subtraction problems
  • Apply subtraction skills to solve real-world word problems
  • Understand the relationship between addition and subtraction through fact families

Interactive Activities

Grocery Store Scenario

Real-World Application

Practice subtraction with real shopping scenarios: 'The store has 46 apples, customers buy 23 apples. How many apples are left?'

Scenario:

Students work through grocery store scenarios where they subtract items purchased from the total inventory.

Method:

Number Line Method: Start at 46, jump back 20 to 26, then jump back 3 to 23. Compare with vertical subtraction.

Practice:

Complete 10 grocery store subtraction problems using both number line and vertical methods.

Subtraction
Problem Solving
Number Sense

Visual Model Comparison

Visual Learning

Use base-ten blocks and drawings to visualize subtraction without regrouping, comparing different representation methods.

Scenario:

Students use base-ten blocks to model subtraction problems and see the relationship between visual and numerical methods.

Method:

Base-Ten Blocks: Show 46 as 4 tens and 6 ones, remove 23 (2 tens and 3 ones), count remaining blocks.

Practice:

Model 5 subtraction problems using base-ten blocks and record the numerical process.

Visual Representation
Place Value
Subtraction

Number Line Subtraction

Strategy Practice

Master the number line method for two-digit subtraction, learning to break down problems into manageable jumps.

Scenario:

Students practice using number lines to solve subtraction problems, learning to make efficient jumps.

Method:

Number Line Strategy: Start at the larger number, make jumps of tens first, then ones.

Practice:

Solve 8 subtraction problems using number lines, showing all jumps clearly.

Number Line
Mental Math
Subtraction

Vertical Subtraction Practice

Algorithm Practice

Practice the standard vertical subtraction algorithm with two-digit numbers that don't require regrouping.

Scenario:

Students practice the standard vertical subtraction method with problems that don't require borrowing.

Method:

Vertical Method: Align numbers by place value, subtract ones first, then tens.

Practice:

Complete 12 vertical subtraction problems, checking answers with number line method.

Vertical Subtraction
Place Value
Accuracy

Word Problem Solving

Problem Solving

Apply subtraction skills to solve word problems involving two-digit numbers without regrouping.

Scenario:

Students read and solve word problems that require two-digit subtraction without regrouping.

Method:

Problem-Solving Steps: Read, identify numbers, choose method, solve, check answer.

Practice:

Solve 6 word problems, showing work and explaining the solution process.

Word Problems
Reading Comprehension
Subtraction

Subtraction Fact Families

Conceptual Understanding

Explore the relationship between addition and subtraction through fact families with two-digit numbers.

Scenario:

Students discover how addition and subtraction are related through fact family exploration.

Method:

Fact Family Method: Given 46 - 23 = 23, find related facts: 23 + 23 = 46, 46 - 23 = 23.

Practice:

Create fact families for 5 different subtraction problems and verify all related facts.

Fact Families
Inverse Operations
Number Relationships

Key Concepts

Subtraction Strategies:

  • • Number line method with efficient jumps
  • • Vertical subtraction algorithm
  • • Visual models with base-ten blocks
  • • Mental math strategies

Problem-Solving Steps:

  • • Read the problem carefully
  • • Identify the numbers involved
  • • Choose an appropriate strategy
  • • Solve and check your answer