Math 7 Q1-W1-D3

1. Quarter 1 | Week 1| Day 3
P r e p a r e d b y : V e a n i c e P . D o s o l

2. Competencies
OBJECTIVES
1. explain the concept of intersection of
sets
2. illustrate a set, an element of a set, a
proper subset, a universal set, a null set,
and the cardinality of set

3. Engage
WHAT’S THE WORD?
Group 1
{𝑎, 𝑒, 𝑖, 𝑡, 𝑛} {𝑒, 𝑖, 𝑡, 𝑛, 𝑥, 𝑦}
Group 2
{𝑐, 𝑒, 𝑟, 𝑠} {𝑎, 𝑏, 𝑐, 𝑒, 𝑟, 𝑠}
Group 3
{𝑡, 𝑜, 𝑖, 𝑛, 𝑚, 𝑠} {𝑛, 𝑜, 𝑢, 𝑣, 𝑖, 𝑡}
ASK:
1.What is the word?
Intersection
2.What did you do to identify the letters?
Find the common elements

4. Explore
ACTIVITY:
Set A Set B Intersection of A
and B
Illustration 1
Set C Set D Intersection of C
and D
Illustration 2

5. Explain
QUESTIONS
1. What have you observed in Illustration 1?
2. How many elements are there in set A? Set B?
3. What have you observed in Illustration 2?
4. How many elements are there in set C? Set D?

6. Explain
QUESTIONS
5. What can you say about the intersection of A and B with
regards to Set A and Set B?
6. intersection of C and D with regards to Set C and Set D?

7. Elaborate
INTERSECTION
The Intersection of two sets A and B, written A∩ B, is the set
of all elements common to sets A and B.
The figures below display A ∩ B. Observe that two sets
are disjoint if and only if their intersection is an empty set.

8. Evaluate
Evaluation:
Given: 𝐴 = {2, 4, 6, 8, 10},
𝐵 = {1, 3, 5, 7, 9},
𝐶 = {1, 2, 3, 4, 5},
𝐷 = {3, 4, 5, 6, 7}
and 𝐸 = {2, 6, 10}.
Find:
1. 𝐴 ∩ 𝐶 4. (𝐴 ∪ 𝐶) ∩ 𝐷
2. 𝐵 ∩ 𝐷 5. (𝐵 ∪ 𝐴) ∩ (𝐷 ∪ 𝐸)
3. 𝐸 ∩ 𝐴

9. Enhancement
Assignment:
Use your assignment notebook to answer the following:
Given the following sets:
A = {0, 1, 2, 3, 4},
B = {0, 2, 4, 6, 8},
C= {1, 3, 5, 7, 9}
Determine the elements of the ff.
1. A U B 3. A U B U C
2. A ∩ B 4. (A U B) ∩ C

10. Enhancement
1. How can you relate
union of sets to our daily
life?
2. What part of the lesson
you found challenging or
interesting?

11. Concluding
Thank you!
See you
next topic
on
“Difference
of Sets”