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Subject: Mathematics
Semester: 1
Period: 1
Week: 2
School Name:
Teacher’s Name:
Subject: Mathematics
Grade Level: Grade 1
Date: Week 2
Lesson Duration: 45 minutes
Week & Period: Week 2, Period 1
Topic: Members (Elements) of a Set
Sub-topic: Counting Elements and Cardinality
Learning Objectives
By the end of the lesson, students should be able to:
Identify the members of a set
Count the number of members in a set
Explain what cardinality means
Previous Knowledge
Students already know:
What a set is
How to count numbers up to 10
Instructional Materials
Mathematics textbook for Grade 1
Lesson Development – ABC Model
A – Anticipation (Warm-up / Starter)
Time: 5–10 minutes
Teacher asks: “What is a set?” and calls on students to give examples. Then the teacher shows a box of crayons and asks, “How many crayons are there in this set?”
B – Building Knowledge (Main Lesson Body)
Time: 25–30 minutes
Definition: Members (or elements) of a set are the things inside the set.
Example: In the set of vowels {a, e, i, o, u}, each letter is a member.
To count the number of members in a set, we use cardinality.
Cardinality is the number of elements in a set.
We write it as n(A) where A is the set.
Examples:
Set A = {a, e, i, o, u} → n(A) = 5
Set B = {Monday, Tuesday, Wednesday, Thursday, Friday, Saturday, Sunday} → n(B) = 7
Set C = {book, ruler, pen} → n(C) = 3
Learners’ Activities (Expanded):
Students count how many vowels are in a given set
Students form small groups and count members of a set of classroom items (e.g., books, pencils)
Students represent their family members as a set and count the members
Assessment Checks:
Teacher checks learners’ ability to write and count members of given sets
Teacher gives sets and asks: “What is the cardinality of this set?”
Notes (Expanded & Detailed):
Each item in a set is one member
Cardinality means how many items are in the set
We use n( ) notation to show the number of items in a set
C – Consolidation (Conclusion & Assessment)
Time: 5–10 minutes
Summary: Members of a set are the things inside it. To count them, we find the cardinality using n(A).
Evaluation Method (Expanded):
Exit slip/quiz: “What is the cardinality of the set {cat, dog, goat, cow}?”
Teacher will collect slips and provide oral feedback.
Assignment (Expanded):
Draw your family and write them as a set. Count the members.
Follow-up Activity:
Next lesson will cover union of sets (addition of sets).
Differentiation / Inclusive Strategies
Use pictures and real items to support learners who struggle with abstract thinking. Allow oral responses for those with writing difficulties.
Teacher’s Reflection (After Class)
What worked well? ___________________________________________
What needs improvement? ____________________________________
Students’ engagement level: ☑ High ☑ Medium ☑ Low