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Subject: Mathematics
Semester: 2
Period: 4
Week: 21
School Name:
Teacher’s Name:
Subject: Mathematics
Grade Level: Grade 1
Date: Week 21
Lesson Duration: 45 minutes
Week & Period: Week 21, Period 4
Topic: Subtraction
Sub-topic: Subtracting Two-Digit Numbers without Regrouping
Learning Objectives
By the end of the lesson, students should be able to:
Subtract 2-digit numbers without regrouping
Use vertical subtraction method
Solve subtraction word problems
Previous Knowledge
Students already know how to add 2-digit numbers and subtract multiples of 10
Instructional Materials
Mathematics textbook, number lines, base 10 blocks, place value charts
Lesson Development – ABC Model
A – Anticipation (Warm-up / Starter)
Time: 5–10 minutes
Teacher asks: “What is 60 – 30?” Students respond. Teacher then says: “Now let’s try 63 – 41.”
B – Building Knowledge (Main Lesson Body)
Time: 25–30 minutes
Subtracting two-digit numbers without regrouping means subtracting when the ones digit of the top number is larger than the ones digit of the bottom number. Example: 63 – 41
Step 1: Write vertically:
63
–41
Step 2: Subtract ones: 3 – 1 = 2
Step 3: Subtract tens: 6 tens – 4 tens = 2 tens
Answer = 22
Word problem: Musa has 52 oranges. He sells 30. How many are left? 52 – 30 = 22.
Learners’ Activities (Expanded)
Students use number lines to subtract by counting backwards.
Students solve problems using base 10 blocks.
Students solve subtraction word problems in groups.
Assessment Checks
Teacher asks: “What is 52 – 20?” “What is 45 – 12?”
Notes (Expanded & Detailed)
Subtraction is taking away. Encourage starting from the ones place before subtracting tens.
C – Consolidation (Conclusion & Assessment)
Time: 5–10 minutes
Summary: Subtract ones first, then tens.
Evaluation Method (Expanded)
Exit slip/quiz: Solve 41 – 21 and 53 – 22. Teacher checks and provides oral feedback.
Assignment (Expanded)
Students complete 5 subtraction exercises from their textbook.
Follow-up Activity
Students create subtraction word problems using real-life objects at home.
Differentiation / Inclusive Strategies
Weaker learners use number lines and objects. Stronger learners solve mentally.
Teacher’s Reflection (After Class)
What worked well? ___________________________________________
What needs improvement? ____________________________________
Students’ engagement level: ☑ High ☑ Medium ☑ Low