Monday, April 12, 2010

Inappropriate Models

We're trying to come up with the generalized process for solving equations. Now that we've got combining like terms and distribution and variables on both sides and sometimes no numbers, just a bunch of different letters and all the combinations of that stuff. What is it that we're really doing when we solve equations?

The supervising mentor that observes and works with our student teachers is a cool old guy, used to teach math, was a principle, still works in schools, and has no shame and no hesitation. He's smart and cheesy in the most compelling way and he fascinates and weirds out the kids when he comes. It's great. He's awesome. Last time he was here, I overheard him talking to a kid about how when we solve equations, we are trying to get x naked. That's why it makes sense to do inverse operations in the opposite order you use to evaluate, because when you're undressing you take off your shoes before your socks.

So I was trying to go with that, and here's what I came up with:

1- Who do you want to get naked? What do you want to solve for?
2- Focus their attention on you. Simplify the environment. Simplify the sides of the equation.
3- Get 'em in a room. Get all the variables (you're into) on one side of the equation.
4- Take off their clothes (shoes before socks, remember!) Use inverse operations to get variable alone.
5- Do they look good naked? Check your answer: does it make the equation true?

I almost told my kids this today, and ended up garbling it in an attempt to make it somewhat appropriate and talking about changing baby's diapers. I actually said "OK, wait, I'm thinking naked kids. No, I mean little kids," out loud. It was hilarious and memorable but pretty gauche.

I thought you guys might have some good ideas, either from experience or improving on this one. I want to laugh this much at school everyday.


  1. Tee hee.

    It's a good analogy but I don't know if I could get through it with students without feeling like a dirty old lady. :-)

    But if you could pull it off I think it would effective. I forget where I read this but (it was just recently I saw it, too...) there are 3 topics immediately interesting to people across cultures: Danger, Power, and Love - but we tend to scrub those topics out of schooling - I've been looking for ways to put them in in ways that are engaging and not threatening.

  2. Ha! I love this, especially since I'm working on solving equations myself with my 8th graders. For some reason I've found myself telling students that variables are rude and want to be all alone in the world. The kids think that's hysterical, and use it to remember that we have to - in the end - have the variable all alone.

  3. I've done something similar playing on the dating thing. Y'know, you want to get that cute little x all alone cause, well he/she's hot. But there are her other friends and that boyfriend of hers to get rid of, etc., etc. I should probably avoid bringing in the taking off the clothes bit to the metaphor I've concocted or I could be dealing with some unpleasant parent phone calls. :)