I may have mentioned this in an earlier posting (how long has it been since I've posted?!), but you may be wondering what all this stuff about Pre-Algebra and butts is about.
I teach "Combining Like Terms" with the metaphor of expressions as creatures... For example, 3y... the 3 (coefficient) is its body and the y (variable) is its butt. It makes it VERY convenient to talk about adding and subtracting like terms, and explaining what happens when you are multiplying/dividing terms.
Today we didn't make it far at all in my plans... we only made it part way through the checking of homework! (I'll post that to the class docs in a moment.)
But, we've been focused on combining like terms for the past week or so, and we'll be in this place for awhile. No homework tonight because we didn't even get to finish checking the homework from last week!