Ordered Pairs
Graphing on the Coordinate Plane
Vocabulary
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coordinate plane
axes
x-axis
y-axis
origin
Coordinates (ordered pair)
x-coordinate
y-coordinate
Coordinate Plane
A coordinate plane is
formed by two
number lines in a
plane that intersect
at right angles. The
point of intersection
is the zero on each
number line.
Coordinate Plane
• The two number
lines are called the
axes.
A coordinate plane is formed by two number
lines in a plane that intersect at right angles. The
point of intersection is the zero on each
number line.
• The horizontal axis is
called the x-axis.
A coordinate plane is formed by two number
lines in a plane that intersect at right angles. The
point of intersection is the zero on each
number line.
• The vertical axis is
called the y-axis.
A coordinate plane is formed by two number
lines in a plane that intersect at right angles. The
point of intersection is the zero on each
number line.
• The point where the
axes intersect is
called the origin.
An ordered pair gives the location of a point
on a coordinate plane. The first number tells
how far to move right (positive) or left
(negative) from the origin. The second
number tells how far to move up (positive) or
down (negative).
The numbers in an ordered pair are called
coordinates. The first number is called the
x-coordinate. The second number is called
the y-coordinate.
The ordered pair for the origin is (0,0).
Click on the picture to see an
example
Example 1: Naming Points Using Ordered Pairs
Write the ordered pair that
names point B.
Step 1 Start at the origin. Move
right along the x-axis until you are
under point B. The x-coordinate of
the ordered pair is 5.
Step 2 Now move up until you
reach point B. The y-coordinate is
6.
So, point B is named by the
ordered pair (5, 6).
Y
8
B
●
6
4
2
O
2
4
6
8
x
Real World Example
Raffle Tickets
RAFFLE Mr. King’s class is conducting a
raffle to raise money for a local charity
organization. The costs of 1, 2, 3, and 4
raffle tickets are shown in the table. List
this information as ordered pairs (number
of tickets, cost).
Number of
Tickets
Cost ($)
1
1.5
2
3
3
4.5
4
6
The ordered pairs are (1, 1.5), (2, 3), (3, 4.5),
and (4, 6).
Y
8
●
6
The points appear to fall on a line.
●
4
●
2
●
O
2
4
6
8
x
4-9 Study Guide Exercises
Use the coordinate
plane at the right
to name the
ordered pair for
each point.
• 1. J
• 2. K
• 3. L
• 4. M
Graph and label each point on the
coordinate plane.
• 5. S(1, 3)
6. T(4, 0)