MathIsimple
Lesson 7-1: Two-Step Addition & Subtraction

Two-Step Addition & Subtraction

Solve problems requiring two operations like library book scenarios through interactive problem-solving activities. Learn to break down complex problems into manageable steps.

30-35 minutesTwo-Step ProblemsLibrary ScenariosProblem Solving
Learning Scenario: Library Book Organization

The Problem:

Our classroom library had 50 books. Students borrowed 18 books, and then returned 12 books. How many books are in the library now?

Two-Step Problem Challenge

Step-by-Step Method:

Step 1: 50 - 18 = 32 books left
Step 2: 32 + 12 = 44 books total
Answer: 44 books in library now
Check: Does this make sense?

Learning Activities

Master two-step problem solving through interactive activities and real-world scenarios

Knowledge Points Display
Activity 1
Learn two-step problem solving with our friendly math teacher. Master identifying problems that need two operations and breaking them into manageable steps.

Key Features:

  • Interactive problem identification
  • Step-by-step problem breakdown
  • Visual thinking frames
  • Progress tracking with milestones

Skills You'll Learn:

  • Step 1: Identify what to find first
  • Step 2: Solve the first operation
  • Step 3: Use the result for second operation
  • Step 4: Check your answer
Interactive Practice
Activity 2
Practice two-step problem solving through library book scenarios. Help organize the library by solving real-world problems step by step.

Key Features:

  • Library book organization scenarios
  • Interactive problem solving
  • Step-by-step guidance
  • Real-world application practice

Skills You'll Learn:

  • Library: 50 books - 18 borrowed + 12 returned = 44 books
  • Step 1: 50 - 18 = 32 books left
  • Step 2: 32 + 12 = 44 books total
  • Answer: 44 books in library now
Examples Library
Activity 3
Explore various two-step problems and practice solving them using different strategies and thinking frames.

Key Features:

  • Multiple problem types
  • Different solving strategies
  • Thinking frame practice
  • Interactive problem solving

Examples:

  • Store: 25 apples - 8 sold + 15 new = 32 apples
  • Class: 30 students - 5 absent + 3 new = 28 students
  • Piggy Bank: $20 - $7 spent + $12 earned = $25
  • Garden: 40 flowers - 12 picked + 18 new = 46 flowers
Two-Step Problem Guide: Step-by-Step

Problem-Solving Steps:

Step 1: Read the problem

Understand what you need to find

Step 2: Identify operations

What operations do you need?

Step 3: Solve first operation

Find the first answer

Step 4: Solve second operation

Use first answer for second operation

Example: Library Books

Problem:

50 books - 18 borrowed + 12 returned = ?

Step 1:

50 - 18 = 32 books left

Step 2:

32 + 12 = 44 books total

Answer:

44 books in library now

Problem Examples

More Two-Step Problems:

Store: 25 apples - 8 sold + 15 new = 32 apples

Class: 30 students - 5 absent + 3 new = 28 students

Piggy Bank: $20 - $7 spent + $12 earned = $25

Garden: 40 flowers - 12 picked + 18 new = 46 flowers

Thinking Frames:

What do I know? Starting amount, what happened first, what happened second

What do I need to find? Final amount after both operations

What operations? Subtraction first, then addition

Does it make sense? Check if answer is reasonable