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Subject: Mathematics
Semester: 2
Period: 4
Week: 21
School Name:
Teacher’s Name:
Subject: Mathematics
Grade Level: Grade 4
Date: Week 21
Lesson Duration: 45 minutes
Week & Period: Week 21, Period 4
Topic: Dividing multiples of 10, 100, 1000 by 2-digit divisors
Sub-topic: Mental division and repeated subtraction
Learning Objectives
By the end of the lesson, students should be able to:
- Understand division as repeated subtraction/grouping with multiples.
- Perform mental division of large numbers by 2-digit divisors.
- Solve real-life scenarios involving division of large quantities.
Previous Knowledge
Students already know basic division facts and division by 1-digit numbers.
Instructional Materials
Mathematics textbook, counters, number lines, chart paper.
Lesson Development – ABC Model
A – Anticipation (Warm-up / Starter)
Time: 5–10 minutes
Teacher asks: “If 600 ÷ 3 = 200, what about 600 ÷ 24?” Students guess and discuss strategies.
B – Building Knowledge (Main Lesson Body)
Time: 25–30 minutes
Teacher explains division of large numbers by 2-digit divisors using estimation and mental math strategies, focusing on how to approximate the quotient first and then verify by multiplication or subtraction. Emphasizes understanding division as repeated subtraction or grouping.
Step-by-step example: 600 ÷ 24
Step 1: Estimate divisor near a round number for easier calculation: 24 ≈ 25
Step 2: Estimate quotient: 600 ÷ 25 ≈ 24
Step 3: Multiply 24 × 24 = 576 (slightly less than 600)
Step 4: Subtract 600 – 576 = 24 (remainder)
Step 5: Since remainder 24 is equal to divisor 24, one more group fits → quotient = 25
Additional Examples:
Example 2: 4,000 ÷ 50
Estimate: 50 is exact divisor, so 4,000 ÷ 50 = 80
Verification: 50 × 80 = 4,000
Example 3: 12,000 ÷ 60
Estimate: 60 is exact divisor, so 12,000 ÷ 60 = 200
Verification: 60 × 200 = 12,000
Teacher uses number lines or counters to model repeated subtraction visually, showing how groups of 24 subtract from 600 until zero or remainder is reached.
Learners’ Activities (Expanded):
- Role-play “distributing goods”: students physically group counters or objects into groups of 24, 36, or 50 to represent division.
- Work in pairs to estimate division problems mentally (e.g., 1,800 ÷ 36, 2,400 ÷ 48), then calculate exact answers using long division or repeated subtraction.
- Use number lines to model division steps for visual understanding.
- Practice estimating quotients by rounding divisors and dividends to nearest tens or hundreds.
Assessment Checks:
- Estimate the quotient of 1,800 ÷ 36, then calculate the exact quotient. (Expected: Estimate ~ 50, Exact: 50)
- Calculate 3,600 ÷ 45 using estimation and verify by multiplication.
- Explain why estimating the divisor helps simplify division of large numbers.
- Using repeated subtraction, show how many times 30 goes into 450.
- What is the quotient and remainder when dividing 1,250 by 24?
Notes (Expanded & Detailed):
• Mental division starts with estimating the divisor and dividend to simplify calculations and narrow down possible quotients.
• Repeated subtraction reinforces the concept of division as "how many groups of a number fit into another number" and deepens conceptual understanding.
• Estimation reduces cognitive load and helps verify if answers are reasonable, avoiding mistakes.
• Visual aids like counters and number lines provide concrete understanding of abstract division concepts.
• Practice helps build confidence with large numbers and multi-digit divisors, preparing students for more complex division tasks.
C – Consolidation (Conclusion & Assessment)
Time: 5–10 minutes
Summary: Division of large numbers can be done mentally with estimation and grouping.
Evaluation Method (Expanded):
Exit slip: Solve 3,600 ÷ 45 using estimation first.
Teacher collects and gives feedback.
Assignment (Expanded):
600 ÷ 25, 1,440 ÷ 48, 3,600 ÷ 60.
Create a word problem involving division of items among groups.
Follow-up Activity:
Peer practice of mental division using counters or objects.
Differentiation / Inclusive Strategies
Provide scaffolded steps for struggling learners; advanced learners solve multi-step division problems.
Teacher’s Reflection (After Class)
What worked well? ___________________________________________
What needs improvement? ____________________________________
Students’ engagement level: ☑ High ☑ Medium ☑ Low