13. Introduction:
As we grow up, we experience
groups of things such as our family,
group of toys, group of playmates and
eventually groups of classmates.
15. Direction: Answer the question
below.
Process Questions:
1) How can you group the objects given? Name
each groups.
2) How many groups can you form? Make a list of
it.
16. 3) Is there an object that belongs to
more than one group? What are those
objects?
4) What do you call now these groups
of objects you’ve formed?
17. Values Integration:
1) In what groups do you belong right now?
Write at least two.
2) How are you going to describe the groups
you belong?
3) As a student, in what way does these
groups you mention boost your confidence?
18. Concept Digest:
A group or collection of
objects is called a set. Each
object in a set is called a
member or an element of a set.
19. Example
Set A = { set of objects that can be worn }
= { shirt, blouse, cap }
So “shirt, blouse and cap ∈ A “ means shirt,
blouse and cap are elements of A.
Set B = { set of objects that are yellow }
= { ball, blouse, mango }
So “guava ∉ B “ means guava is not an element
of B.
20. Well-defined set is a set with an exact
object or element.
Example:
• {a subject in Grade 7}
Yes it is a well-defined set, because it is
clear whether a subject is taught in Grade
7.
• {a popular actor}
No, because some people may consider
an actor popular while others do not.
21. Evaluation
A. Direction: Fill in each blank with ∈ or ∉.
Set A = {even numbers between 0 and 10}
Set B = {letters of the alphabet between c and j}
Set C = {months of the year ending in “ber”}
1) 2 ___ Set A 6) g ___ Set B
2) August ___ Set C 7) December___Set C
3) b ___ Set B 8) e ___ Set B
4) 12 ___ Set A 9) October ___ Set C
5) January ___ Set C 10) 5 ___ Set A
22. B. Direction: State whether the
collection is a well-defined set.
1) {a favorite fruit}
2) {a student in your class}
