📖

Counting Back by Tens and Ones

Subtraction Within 100: Mental Math Strategies

Day 38of 180
Week 8of 36
30Minutes
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🖨️ Download Worksheet (PDF)🧮 Download Math Practice (PDF)
🎯 What You'll Learn

Learning Objectives

1

Subtract two-digit numbers by counting back tens and ones

2

Use a hundred chart to visualize subtraction strategies

3

Develop confidence in mental math problem-solving

📖 Scripture Connection

Proverbs 16:16

“How much better it is to get wisdom than gold! Yes, to get understanding is to be chosen above silver.”

— Proverbs 16:16 (WEB)

Just as we carefully count and solve math problems, wisdom requires careful thought and strategic thinking

📦 Materials Needed

  • Hundred chart
  • Pencil
  • Worksheet
  • Base-ten blocks (optional)
📚 Step-by-Step

Lesson Plan

1Opening (5 min)

Welcome to today's BibleMouse math adventure! Let's review how we've been learning to subtract using different strategies.

💭 Review Question: Can you show me how we subtracted tens in our last lesson?
2Teaching (10 min)

Today, we'll learn a powerful mental math strategy for subtraction - counting back by tens and ones.

📌 Key Talking Points:
  • Look at our hundred chart - it's like a map for numbers!
  • When we subtract, we can jump back in tens first, then adjust with ones
  • This makes subtraction faster and easier in our minds
💬 Discussion Questions:
  • What do you notice about moving on a hundred chart?
  • How can counting back help us solve subtraction problems?
3Activity: Hundred Chart Subtraction Adventure (12 min)
hands-on

Students will practice subtraction by physically moving on a hundred chart

📝 Instructions:
  1. Start with a two-digit subtraction problem
  2. First, count back tens on the hundred chart
  3. Then, count back the remaining ones
  4. Write down each step of your journey
🔄 Variations:

Simpler: Use problems with smaller numbers, work with parent guidance

Challenge: Create your own two-digit subtraction problems to solve

4Closing (3 min)

Let's celebrate our math learning today!

📝 Review Questions:
  • What strategy did we learn today?
  • How does counting back help us subtract?

Coming up: Tomorrow, we'll learn how to add up to subtract - another exciting mental math strategy!

👨‍👩‍👧 For Parents

Teaching Notes

📚 Background:

Mental math strategies help children develop number sense and computational fluency

💡 Teaching Tips:
  • Be patient and encouraging
  • Use physical movement on the hundred chart
  • Praise effort over perfection
🤔 Common Struggles:

Children might get confused tracking tens and ones

👀 Signs of Understanding:

Confidence in moving on the hundred chart, understanding the strategy

🚀 Want More?

Extension Activities

  • Create a subtraction game using the hundred chart
  • Practice subtraction with base-ten blocks
  • Use BibleMouse Printables Library for additional worksheets

Ready for Tomorrow?

Great job completing today's lesson!

Continue to Day 39 →Back to Math