School : Junior High School 1
Wates
Subject : Mathematic
Class/Semester : VII/2
Standard Competence : 4. Using
concepts of set and Venn Diagram in problem solving.
Basic Competence : 4.1. Understanding the definition and the
notation of set and how to state a sets.
Indicators : 4.1.1. To state
daily problems in a set.
4.1.2. To mention the element
of a set.
4.1.3. To
mention non element of a set.
4.1.4. To represent a set by
description.
4.1.5. To represent a set using
tabular form.
4.1.6. To
represent a set using set-builder form.
Time Allocation : 1 x 20 minutes
I.
Learning
Objectives:
1. Students are able to state daily problems in a set.
2. Students are able to mention
the element of a set.
3. Students are able to
mention non element of a set.
4. Students are able to represent
a set by description.
5. Students are able to represent
a set using tabular form.
6. Students are able to
represent a set using set-builder form.
II.
Materials:
SET
A is collection
of animals that have 4 legs.
A is set of animals that
have 4 legs.a.jpg)
B is set of fruits.
A. Meaning of Set:
A set is a collection of well defined and
distinct objects.
Capital letters
are used to indicate the set’s name. The symbol of a set is {}.
Example:
1. Collection
of handsome boys. (Not a set because the objects are not well defined)
2. Collection of big houses. (Not a set because the objects are not well defined)
A. Elements of a Set:
Objects in a set
are called elements of a set.
Notation of the element
is Î.
Notation of non element
is Ï.
Example:
1. Buffalo, sheep, bison, rhinoceros, cow are
elements of set A. Duck is not element of A.
Buffalo, sheep,
bison, rhinoceros, cow Î A. Duck Ï A.
2. Watermelon, lemon, strawberry, avocado, banana,
apple, pineapple are elements of set B. Grape is not element of B.
Watermelon, lemon,
strawberry, avocado, banana, apple, pineapple Î B. Grape Ï B.
B. There are three ways to represent a set, such:
1. By description
Example:
a. C is set of prime numbers less than 15.
b. D is set of natural numbers between 2 and 13.
2. Using tabular form: listing each member of the set.
Example:
a. A = {buffalo, sheep, bison, rhinoceros, cow}
b. B = {watermelon, lemon, strawberry, avocado, banana,
apple, pineapple}
c. C = {……………………………….}
d. D = {……………………………….}
3. Using the set-builder form
Example:
a. C = {x
| x < 15, x is prime numbers}
Read as: C is the
set of all x, such that x is less than 15 and x is prime numbers.
b. D = {………………………………}
III.
Learning
method:
Methods: expository, asking and answer,
discussion.
IV.
Learning scenario:
|
Teacher activities
|
Students activities
|
Duration
|
|
A. Introduction
|
||
|
1. Teacher greets students,
“Good afternoon my students!”
Teacher asks
students’ condition, “How are you?”
“Who is absent
today?”
|
1. Students also greet teacher, “Good afternoon
Mom!”
Students answer,
“Very well, thank you.”
“None Mom.”
|
1 minute
|
|
2. Teacher tells students that in this meeting
they will learn about set, “Let’s begin our class now. Today we will talk about set. In the end
of the lesson, you will be able to state daily problems
in a set, mention the element
and non element of a set, represent a set by definition, using tabular form,
and using the set-builder form”
|
2. Students listen carefully what teacher said.
|
1 minute
|
|
B. Main Activities
|
||
|
1. Teacher write the title “SET” in the white
board. Then, teacher show picture A and B.
Teacher tells a
story about picture A, “Last holyday, Absari tells me that she went to Gembira
Loka Zoo. In the zoo, Absari looks buffalo, sheep, bison, rhinoceros, and
cow.”
|
1. Students also write the title “SET” in
her/his book.
Students look at
the picture. Students pay attention to teacher’s story.
|
1 minute
|
|
2. Teacher explains, “We also can say that
picture A is collection of animals that have four legs. In the other word, A
is set of animals that have four legs.”
Then teacher
write on the board: A is collection
of animals that have 4 legs. A is set of animals that have four legs.
|
2. Students listen carefully and also write in
his/her book.
|
1 minute
|
|
3. Then teacher tells story about picture B, “Yuliana
likes fruits very much. She likes watermelon, lemon, strawberry, avocado,
banana, apple, pineapple. So, what is the name of the set consist of
watermelon, lemon, strawberry, avocado, banana, apple, pineapple?”
Teacher asks students
whose answer the question, “Can you
write your answer?”
|
3. Students listen to teacher story and answer,
“Set of fruits.”
Then, student
writes the answer on the board.
|
1 minute
|
|
4. Teacher asks students, “So, what is the
meaning of set?”
Teacher explains
and writes on the board: “A set is a collection of well defined and distinct objects. Capital letters are used to indicate the
set’s name. The symbol of a set is {}.”
|
4. Students answer: “Set is collection of
objects.”
Students listen
to teacher explanation and also write in his/her book.
|
1 minute
|
|
5. Teacher asks students, “Can you give example of
not well defined objects?”
Teacher says,
“Collection of handsome boys are not well defined objects. Then, the other
example is collection of big houses. They are not a set.”
|
5. Students answer: collection of handsome boy.
Students pay
attention to teacher’s statement.
|
1 minute
|
|
6. Teacher explains and writes on the white
board, “Objects in a set are called elements of a set. Notation of the
element is Î. Notation of non element is Ï.”
Teacher asks
students, “What are the elements of set A? Is duck element of set A?”
Then, teacher
write on the board: Buffalo, sheep, bison, rhinoceros, cow are elements of A.
Duck is not element of A. Buffalo, sheep, bison, rhinoceros, cow Î A. Duck ÏA.
|
7. Students listen and also write in his/her
book.
Students answer,
“Buffalo, sheep, bison, rhinoceros, cow Î A. Duck ÏA”
|
1 minute
|
|
7. Teacher asks students, “What are the elements
of set B? Is grape element of set B?”
Then teacher
asks one students to write the answer on the board, “Can you come to write
the answer?”
|
8. Students answer: watermelon, lemon,
strawberry, avocado, apple, pineapple, banana ÎB. GrapeÏ B.
|
1 minute
|
|
8. Teacher explains and write on the board, “There
are three ways to represent a set: by description, using tabular form, and
using set-builder form.” Then teacher give example how to represent a set by
description: C is set of prime numbers less than 15. D is set of natural
numbers between 2 and 13.
|
9. Students pay attention to teacher’s
explanation.
|
1 minute
|
|
9. Teacher gives example how to represent a set
using tabular form/
listing each member of the set and write on the board: A = {buffalo, sheep, bison, rhinoceros,
cow}. Then teacher asks student to represent set B, C, and D, “Can you
represent set B, C, and D by using tabular form?”
Teacher asks
student to write the answer on the board.
|
10. Students pay attention to teacher’s
explanation.
Student answer:
B = {watermelon, lemon, strawberry, avocado, banana, apple, pineapple}, C=
{2, 3, 5, 7, 11, 13}, D = {3, 4, 5, 6, 7, 8, 9, 10, 11, 12}.
|
2 minutes
|
|
10. Teacher gives example how to represent a set
using set-builder form and write on the board: C = {x | x < 15, x Î prime numbers}. We can read as: C is the set
of all x, such that x is less than 15 and x is prime numbers. Then teacher
asks student to represent set D, “Can you represent set D using set-builder
form?”
Teacher asks
student to write the answer on the board.
|
11. Students pay attention to teacher’s
explanation.
Student answer:
D = {x | 2 < x < 13, x Î natural numbers}
|
2 minutes
|
|
11. Teacher says, “Now, I have exercise for you.
Please make grubs contain 2 people and discuss about the exercise, after you
finish, then present your answer in front of class.”
|
12. Students make grubs contain 2 people, then
discuss about the exercise.
|
2 minutes
|
|
12. Teacher walks around the class and look
students’ answer. Teacher asks students to present their answer, “Who is
finish? Please come to write your answer.”
|
13. Students from grubs 1,2,3,4 come in front of
class and write the answer.
|
3 minutes
|
|
C. Closing
|
||
|
1. Teacher says, “Okay, the conclusion of this
meeting: A set is a collection of well defined and distinct objects. Objects in a set are called elements of a
set. Three ways to represent a set: by description, using tabular form, and
using set-builder form.”
|
1. Students pay attention to teacher’s say.
|
1 minute
|
|
2. Teacher asks students, “Don’t forget to do
your homework. Because time is up, so we will continue our lesson next week.
Good afternoon, have a nice weekend, bye bye, and see you.”
|
2. Students answer, “Good afternoon Mom. Bye bye
and see you Mom.”
|
|
I. Learning
source and media:
Learning
source:
Dr.
Marsigit, MA. 2009. Mathematics for Junior High School Year VII. Jakarta: Penerbit
Yudhistira.
Media: Picture of animals and
fruits.
II. Assessment:
A. Technique :
written test.
B. Question :
Exercise
1. What is the set that can be formed by 0, 1, 4,
9, 16, and 25?
2. Write set H = {h | 2h – 5 < 7, h Î whole numbers} using tabular form.
3. Write set J = {2, 4, 6, 8, 10, 12, 14, 16}
using set-builder form.
4. Write set K = {1, 4, 6, 8, 9, 10, 12, 14, 15}
using set-builder form.
Homework:
1. Write L = {0, 1/2, 1/4, 1/8, 1/16, 1/32} using
set-builder form.
2. Write M = {m | -17 < 2m ≤ -1, m Î whole numbers} using tabular form.
C. Answer:
Exercise:
1. G = {quadratic numbers less than 26} or
G = {g | g2 <
26, g is whole numbers}
2. H = {0, 1, 2, 3, 4, 5}
3. J = {j | 1 < 2j < 15, j is natural
numbers}
4. K = {k | k < 16, k is composite numbers}
Homework:
1. L = {x | (1/2)x ≤ 1/16, x Î even numbers}
2. M = {}
Yogyakarta, 4th April 2012
Microteaching teacher,
Margaretha Madha Melissa
Tidak ada komentar:
Posting Komentar