DEMONSTRATION LESSON PLAN IN MATHEMATICS 8

I. OBJECTIVES:
At the end of the lesson, the students are expected to:
1. Define Cartesian coordinate system,
2. Plot the given points, and
3. Name the location of each given points.

II. SUBJECT MATTER:

a. Topic: Cartesian coordinate system
b. Reference: Elementary Algebra
By: Fernando B. Orines and Catalina B. Manalo
c. Materials: Cut outs, Pictures, Chalk, Chalkboard, and Eraser
d. NCBTS: Domain 4: Curriculum
e. Value Focus: Accuracy
f. Teaching Strategy: Inductive Method

III. LEARNING ACTIVITIES:

A. Preparatory Activities
1. Prayer (This shows Spiritual intelligence)
2. Checking of Attendance
3. Collecting of Assignment

B. Review
What was our lesson last meeting? Our lesson last meeting was about the
Number line.
What is number line? Number line is a picture of a straight line
On which every point is assumed to
Correspond to a real number and every
Real number to a point.

In a number line, where do we find the positive numbers? Positive numbers lie on the right side of
zero.

How about the negative numbers? Negative numbers lie on the left side of
zero.

What do you call to the one that divide the number line It is called as the origin or the zero.
in two symmetric halves or the positive and negative
numbers?
C. MOTIVATION:

QII QI

Market Petron

House School

QIII QIV

I have here a picture. Assuming that this picture is

A map, divided into four parts called quadrant I, II,
III, and IV. There is a point in the center, assuming
that it is a crossing.
From the crossing going to the right, we will find the
Petron. From the crossing going up, we will find the
market. From the crossing going to the left, we will
find the house. And from the crossing going down,
we will find the school.

In what part of the map can you see the Petron? In quadrant I, ma’am!

How about the School, in what part of the map? In quadrant IV, ma’am!

Next, in what quadrant can you see the house? In quadrant III, ma’am!

How about the market, in what part of the map? In quadrant II, ma’am!

What can you say about the drawing? (The students have different answers)

Very Good!
This drawing is related to our new lesson today.
What do you think is our lesson? Cartesian coordinate system.

IV. LESSON PROPER:

1. Presentation
Today, we will study about theCartesian coordinate
system.
I have here a picture. Do you know who this man is? No, ma’am!
This man is Rene Descartes. He was born on
March 31, 1596, and died on February 11, 1650. He
Was a French Philosopher, mathematician, and a
Writer who spent most of his adult life in Dutch
Republic. And, he introduced this Cartesian
coordinate system.

2. Discussion
What is Cartesian Coordinate System? A Cartesian coordinate system is made
Of two perpendicular real number lines.
It is a system for identifying points in
Space.
Correct!
Cartesian coordinate system is also called as
rectangular coordinate system. It consists of a
horizontal axis and vertical axis. The horizontal
number line is called the x-axis while the vertical
number line is called the y-axis.

What do you call the point of intersection of The intersection of the two axes is
the horizontal and vertical axis? Called as the point of origin.

That’s right!
The axes intersect at the origin. At the origin, the
Value of x is zero and the value of y is zero.

The two lines that divide the plane into four

Portions called quadrant.

What are those quadrants? The first quadrant (QI), the second
Quadrant (QII), the third quadrant
(QIII), and the fourth quadrant (QIV).

Very Good!
A point that is located on the first quadrant has
the sign (+,+), on the second quadrant is (-,+),
on the third quadrant is (-,-), and on the fourth
quadrant is (+,-).

An ordered pair (x,y) can be plotted on the

Cartesian coordinate system and this
corresponds to a plane. The first component of
the ordered pair is called abscissa while the
econd component is called ordinate.

Let us plot the following points on the Cartesian plane.

1. A(3,2)
2. B(-4,1)
3. C(3,-1)
4. D(0,-5)
5. E(0,0)

To plot point A(3,2), we will locate positive 3 along the

x-axis then we will go down 2 units.

In what quadrant do we find point A(3,2)? It is located in the first quadrant.

Similarly, to plot point B(-4,1), what should we do? To plot point B(-4,1), locate negative 4
Along the x-axis then, go up 1 unit.

In what quadrant do we find point B(-4,1)? It is located on the second quadrant.

(The teacher shall explain how to plot the remaining

points on the Cartesian coordinate system.)

V. GENERALIZATION
What is Cartesian coordinate system? Cartesian coordinate system is made up
Two perpendicular real number lines. It
Is a system for identifying points in
space.

How many axis does the Cartesian coordinate system? It consists of two axes which are the
Horizontal and vertical axis.

What is origin? Origin is the point of intersection of the

Two perpendicular number lines.

How many quadrants do we have in Cartesian coordinate There are four quadrants. The Quadrant
system? What are those quadrants? I,II,III, and IV.

Identify their corresponding signs. The quadrant I has the sign of all
Positive. The quadrant II has the sign of
negative and positive. The quadrant III
 has the sign of all negative, and the
quadrant IV has the sign of positive and
negative.
VI. APPLICATION
Direction: Plot the following points on
Cartesian plane.
1. A(2,3)
2. B(0,0)
3. C(-3,1)
4. D(-1.5,-2.5)
5. E(3,-2)

We can also use Cartesian coordinate system in our

real life situation. We can use it like a map in locating
places or landmarks.

VII. EVALUATION
Plot the given points using only one Cartesian plane.
1. M(2,5)

2. N(-3,2)
3. L(0,-2)
4. P(3,-5)
5. Q(4,0)

VIII. ASSIGNMENT

Without plotting, name the location of each given point.

1. (-3,-1) 1. Quadrant III

2. (5,4) 2. Quadrant I
3. (-2,3) 3. Quadrant II
4. (-4,1) 4.Quadrant II
5. (2,5) 5. Quadrant IV
6. (0,0) 6. Origin
7. (0,5) 7. Along the y-axis
8. (3,0) 8. Along the x-axis
9. (-1,0) 9. Along the x-axis
10. (0,-5) 10. Along the y-axis