📖

Thinking Addition to Subtract

Subtraction Fluency Within 20

Day 22of 180
Week 5of 36
30Minutes
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🖨️ Download Worksheet (PDF)🧮 Download Math Practice (PDF)
🎯 What You'll Learn

Learning Objectives

1

Understand subtraction as finding the missing addend

2

Use related addition facts to solve subtraction problems

3

Develop mathematical thinking as a way to honor God's gift of reasoning

📖 Scripture Connection

Proverbs 2:6

“For Yahweh gives wisdom. Out of his mouth comes knowledge and understanding.”

— Proverbs 2:6 (WEB)

Just as we discover missing numbers through careful thinking, God provides wisdom and understanding to solve life's challenges

📦 Materials Needed

  • Subtraction flashcards
  • Number line
  • Counters
  • Pencil and paper
  • BibleMouse Resource Guide: Grade 2 Math
📚 Step-by-Step

Lesson Plan

1Opening (3 min)

Review yesterday's subtraction facts and connect to today's lesson about thinking addition to subtract

💭 Review Question: Can you remember how addition and subtraction are related?
2Teaching (10 min)

Demonstrate how subtraction can be solved by thinking about the missing addend in an addition problem

📌 Key Talking Points:
  • When we subtract, we can think about what number makes the addition fact complete
  • Example: 15 - 7 = ? is the same as asking 'What number plus 7 equals 15?'
  • This helps us solve problems by using what we know about addition
💬 Discussion Questions:
  • How can knowing addition facts help us subtract?
  • What happens when we switch the order of numbers in a subtraction problem?
3Activity: Missing Number Detective (12 min)
discussion

Use counters and flashcards to practice finding missing addends through subtraction

📝 Instructions:
  1. Draw a subtraction problem from the BibleMouse flashcard set
  2. Use counters to represent the total number
  3. Remove some counters to represent the number being subtracted
  4. Count how many counters remain to find the answer
🔄 Variations:

Simpler: Use numbers within 10

Challenge: Use two-digit numbers within 20

4Closing (3 min)

Recap how thinking addition helps solve subtraction problems

📝 Review Questions:
  • What strategy did we learn today?
  • How can thinking about addition help us subtract?

Coming up: Tomorrow we'll learn about counting back on a number line to subtract

👨‍👩‍👧 For Parents

Teaching Notes

📚 Background:

Subtraction as finding a missing addend is a key mathematical thinking skill

💡 Teaching Tips:
  • Be patient and use lots of visual demonstrations
  • Encourage your child to explain their thinking
  • Use everyday situations to practice math skills
🤔 Common Struggles:

Children often find it challenging to reverse addition and subtraction thinking

👀 Signs of Understanding:

Child confidently using addition knowledge to solve subtraction problems

🚀 Want More?

Extension Activities

  • Create a subtraction fact family poster
  • Play 'Missing Number' game using BibleMouse flashcards
  • Practice subtraction problems while singing a BibleMouse math song

Ready for Tomorrow?

Great job completing today's lesson!

Continue to Day 23 →Back to Math