1. Functions
Sylvester McMonkey McBean then tells the original Star-Belly Sneetches that he’s created a machine that takes stars OFF of bellies. — seussblog.wordpress.com 
      
Source page on kathmanduk2.wordpress.com | Source image on s1.hubimg.com 

2. Web Search What is a function?
Students will search for the definition of a function

3. Math Talk
Have students discuss their findings and share their conclusions about what a function is.
FIRST think on your own (3 minutes) THEN share your thoughts with your group. Record your group’s findings

4. The Sneetches
As you watch the following video, THINK about how you can relate the Sneetches to functions
Have students watch the video – you can fast forward in the interest of time, but students do enjoy it. At the end of the math portion of the lesson, you can extend it to a conversation on bullying.

5. Math Talk – Is the plain belly sneech always the input?
Have students pair and share to answer this question – elicit that if the plain belly sneech is the input the star belly sneech is the output but it the star belly sneech is the input then the plain belly sneech is the output

6. Math Talk – How does this image relate to functions in math?
y = x + 2
Elicit from students that the value of x goes in, 2 is added and results in the value of y

7. Math Talk – what can you conclude about the following function?
y = 3x + 2
If x = 2
If x = 3
Elicit a conclusion that the output is dependent on the input.
Have students graph the line using an online tool or paper and pencil

8. Graph the following. Are they all functions?
y = 3x + 2
y = 3 – x
y = x2
Have students graph the equations using an online tool or paper and pencil

9. Math Talk Are the following relations functions?
{(2, 3), (–1, 4), (4, 5), (–2, 3)}
{(4, 4), (–2, 3), (4, 2), (3, 4)}
Discussion about 4 having two different outputs and is therefore not a function.

10. Is this a Function?

11. Is this a Function?
Discussion as to why this image does not depict a function

12. Summary Math Talk What is a function
Summary Math Talk What is a function? (In your own words) Create an example to share