Lesson 1-1: Two-Digit Addition Without Regrouping

Two-Digit Addition Without Regrouping

Learn to add two-digit numbers using the break apart strategy. Practice with classroom library scenarios and master adding tens and ones separately.

25-30 minutesBreak Apart StrategyInteractive PracticeReal-World Scenarios

Learning Scenario: Classroom Library Corner

The Problem:

Our classroom library has 23 story books and 15 science books. How many books do we have in total?

23 + 15 = ?

Break Apart Strategy:

Step 1: Break apart the numbers

Step 2: Add tens first (20 + 10 = 30)

Step 3: Add ones second (3 + 5 = 8)

Step 4: Combine results (30 + 8 = 38)

Learning Activities

Master two-digit addition through interactive activities and real-world scenarios

Knowledge Points Display

Activity 1

Learn the break apart strategy with our friendly math teacher and interactive visual aids. Master adding tens and ones separately.

Key Features:

Interactive math teacher with step-by-step guidance
Visual break apart demonstration
Tens and ones place value tools
Progress tracking with milestones

Skills You'll Learn:

Break apart strategy: 23 + 15 = (20 + 10) + (3 + 5)
Adding tens first: 20 + 10 = 30
Adding ones second: 3 + 5 = 8
Combining results: 30 + 8 = 38

Interactive Practice

Activity 2

Practice two-digit addition through engaging classroom library scenarios. Help organize books and solve real-world problems.

Key Features:

Classroom library organization
Interactive number card dragging
Visual book counting
Step-by-step problem solving

Skills You'll Learn:

23 story books + 15 science books = 38 total books
Break apart: (20 + 10) + (3 + 5) = 30 + 8 = 38
Vertical addition practice
Real-world application

Examples Library

Activity 3

Explore various two-digit addition problems without regrouping. Practice with different scenarios and number combinations.

Key Features:

Multiple problem types
Visual representations
Step-by-step solutions
Interactive practice

Examples:

34 + 25 = (30 + 20) + (4 + 5) = 50 + 9 = 59
42 + 36 = (40 + 30) + (2 + 6) = 70 + 8 = 78
17 + 22 = (10 + 20) + (7 + 2) = 30 + 9 = 39
56 + 23 = (50 + 20) + (6 + 3) = 70 + 9 = 79

Break Apart Strategy: Step-by-Step

Example: 23 + 15

Step 1: Break apart the numbers

23 = 20 + 3

15 = 10 + 5

Step 2: Add tens first

20 + 10 = 30

Step 3: Add ones second

3 + 5 = 8

Step 4: Combine results

30 + 8 = 38

Vertical Addition

+15

No regrouping needed!

Practice Problems

Try These Problems:

34 + 25 = ?

Hint: (30 + 20) + (4 + 5)

42 + 36 = ?

Hint: (40 + 30) + (2 + 6)

17 + 22 = ?

Hint: (10 + 20) + (7 + 2)

Real-World Scenarios:

Art Class: 28 crayons + 31 markers = ? art supplies

Lunch Count: 24 sandwiches + 15 salads = ? meals

Field Trip: 36 students + 13 chaperones = ? people

Ready for the next lesson?

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