So I'm planning for next year, and I am trying to provide a "Why activity" for why students need to learn about graphing. I'm thinking about having them try to explain something that involves the relationship between two factors that is dynamic that most 8th graders have probably encountered in their daily lives, or maybe something that they will be able to easily learn and then they are tasked with describing this relationship to a friend without drawing pictures, using hand motions, and simply talking at them. The problem is that I don't know what I want them to discuss and try to describe. Any ideas? I am hoping this will illustrate the need for graphing in science. If you guys have any other ideas, I'm completely open as well.

It might be fun to play around with some misleading graphs in different advertisements. This would definitely show them why they need to understand graphing and how to make graphs. It might also be fun to give them a bunch of data written in a table. Then to give them the same data in a graph and have them tell you why graphing is important.

Here is something I would consider (ignore the questions--they relate to calculus, but you can do it without the differentiability and continuity considerations): http://math.rutgers.edu/~greenfie/mill_courses/math151a/pdfstuff/w5.pdf If you have access to a sink and can get different shaped contain ers (don't have to be exactly like those), and then have them describe the height of water in the container as a function of time. It's hard to explain exactly how it is filling without a graph in less you are pretty vague. Perhaps it's a little too tough--I'm not sure?

I always talk about graphing in terms of a location. "once upon a time, centuries ago, when I was a little girl, there was no such thing as GPS. There was no Google Earth, no mapquest. We went to the local gas station, where there were things called maps, free for the taking... you took one while your gas was being pumped..." Graphing is all about a locus of points, so I think that taking a drive, or a bike ride, is the most logical explanation of it.

Great ideas guys!! I will probably use all of them in the course of the year. @Mathemagician: I love the idea. Since you're using height, it's definitely doable for them. I almost thought you meant to describe the volume over time though, which they probably would have a bit of trouble with. xD

There is a new book published by Math Solutions called It's all Connected: The Power of Representation to Build Algebraic Reasoning (gr 6-9). I have used it students in grades 6 - 8, and the sample graphs (and scaffolding of prompts) has helped build their understanding of how graphs help us understand the relationship between quantities. http://store.mathsolutions.com/product-info.php?Its-All-Connected-pid724.html?aid=e9GNT9 The sample lesson (click on "lessons") has a graph that the kids love, illustrating the speed at which a rumor spread through a classroom. That graph could spark some interesting dialogue, and, hey, it's free!

When I taught scatter plots in Algebra, I used a PowerPoint that had a bunch of pictures of celebrities on it (for fun, I also included a baby picture of myself). I had them guess the age the person was in the picture. Then, I gave them the actual ages and had them plot (guess vs. actual). The kids always loved this activity and they always remembered creating a line of best fit. Creating a line of best fit may not be what you want to do, but if you could take this activity and spin it how you would like, your students will have a lot of fun with it, especially if you pick stars that they have a connection with. This activity was one of the only that I can say that I had everyone's attention and that everyone always remembered.