1. The Cartesian PLane
Let’s start graphing!

2. Introduction to x-y plane
You learned about the basic (counting) number line back in elementary school:
Later on, you were introduced to zero and negatives, which completed the number line:

3. Descartes' breakthrough was in taking a second number line, standing it up on its end, and crossing the first number line at zero:

4. Ordered Pairs
An 'ordered pair' is simply two numbers in a certain order. For example, the numbers '2' and '3' can form two ordered pairs:
2, 3       and      3, 2
In mathematics, we use two numbers to accurately locate a position on a rectangular grid, like this:

5. Coordinate system origin
On a graph grid, the point (0,0) is called the 'origin'
y coordinate
origin
The first coordinate of a plotted point is called the 'x' coordinate
X coordinate
The second coordinate of a plotted point is called the 'y' coordinate

6. Let’s Graph 2 1 (2, 4) ● ● ● (2, 4) (-4, 3) ● (-4, 3) (-5, -4) ●
(3, -3) ●
(3, -3) ● ● 3 4

7. Your turn: which quadrant will the point lie?1 2 3 4
(2, -3)
(-2, -1)
(5, -5)
(-2, 1)
(1, 5) 1 ● 4 ● 3 ● ● 4 ● 2