1. © 2011 The Enlightened Elephant

2. Teacher Tips The next slide visually explains the slope formula.
When viewing the next slide:
To help explain how to find “vertical change” the yellow line and the red line will appear on the graph first.
The yellow line represents the length of y2 and the red line is y1.
Ask students if they can tell you the length of the yellow line and the red line and/or explain their lengths using the y-axis as a reference.
The red line will overlap onto the yellow line so that students can see (and you can explain) that if you remove the red line section (length y1) from the yellow line (length y2) the resulting length will be “vertical change”
To help explain how to find “horizontal change” the orange line and the purple line will appear on the graph next.
The orange line represents the length of x2 and the purple line is x1.
Ask students if they can tell you the length of the orange line and the purple line and/or explain their lengths using the x-axis as a reference.
The purple line will overlap onto the orange line so that students can see (and you can explain) that if you remove the purple line section (length x1) from the blue line (length x2) the resulting length will be “horizontal change”
© 2011 The Enlightened Elephant

3. Slope To Find Vertical Change Vertical Change Horizontal Change
To Find Horizontal Change
Horizontal Change
Horizontal Change
What are the lengths of the yellow and red lines?
What are the lengths of the orange and purple lines?
Slope =
Vertical Change
Horizontal Change =
© 2011 The Enlightened Elephant

4. Find the slope between (5, 3) and (9,9)
Example
Horizontal Change
Vertical Change
Find the slope between (5, 3) and (9,9)
Slope =
Vertical Change
Horizontal Change = = =
© 2011 The Enlightened Elephant

5. You Try It! 1. Find the slope between (2, -1) and (4, 2)
(4,2)
(2,-1)
Slope =
Vertical Change
Horizontal Change = =
2. Find the slope between (-5, 1) and (-2, -3)
(-5,1)
(-2,-3)
Slope =
Vertical Change
Horizontal Change = =
© 2011 The Enlightened Elephant