In this activity, students interpret the slope and intercepts of the line they drew to fit the data in the context of the situation and discuss the limitations of the mathematical model (MP4). 

This activity can be extended by having students investigate if temperature on other continents or across continents fits the same pattern that was found for North America.

If students are using “units” to describe their slope, consider asking:

• “Tell me more about what the slope means for your model.”
• “How could you use specific units to help you make the meaning more clear?”

Invite students to share their responses. Discuss the limitations and uses of the model. Consider asking the following questions:

• “What are some limitations of the model?” (The data the model is made from are only from North America, so may not be good at predicting cities on other continents.)
• “Do limitations mean that the model is not good?” (No, it just means that we have to be aware of when we can use it and when we can’t use it. Our model is pretty good for latitudes between 20 and 65 degrees north and for locations in North America.)
• “What questions do you have about predicting temperature?”
• “How could you extend your investigation of predicting temperature?”