Background: I was teaching about real-life situations of systems of equations. I showed a relatively dull video about buying CDs and DVDs (yes, I know, "no one buys CDs anymore, we have iTunes") when a kid asked me that lovingly hated question "when are we ever going to use this?" I have tried very hard to answer this question quickly but yesterday I decided to take a larger bite: I opened up my web browser and went to two cell phone websites - mycricket.com and metropcs.com.
We spent the next 30 minutes arguing which phones were better, how much they cost, how do you know the right cell phone plan for you - in a generally disorganized shouting match. It was fascinating.
The most interesting thing that came out of it, though, was that my students kept saying "we are just going to pay our bills until we can't. Then the phone will be off for a little while until we can again."
This set me aback. Pay our bills until we can't? "Don't you want to plan ahead?" I asked, incredulously. "No! If I want to buy something, I'm going to buy it!"
This was the sentiment of pretty much everyone in the group. For some reason, their brains have been trained (by media, socioeconomic status, neighborhood violence, or whatever) to have an intense instant gratification bent. I tried my very best to argue that you could think about how much money you have saved and make a better determination on keeping your phone on, but apparently that is not an issue for them. It was strange.
Today I continued by actually asking them to make equations for phones and plans they wanted. We talked about why you would want a certain plan for a bit, and then graphed them to see where they interested (the solution to a real-life system of equations). And I pointed out the fact that some phones + plans are cheaper at the beginning, but then get more expensive later on. We even compared the cost of STEALING a phone (the y-intercept, or phone cost, becomes zero).
Basically, it was very fruitful and interesting and I'm glad I disobeyed what I had planned to do these two days.