I am not a fan of full-fledged lesson plans but I am also not a fan of not making any plans. Normally, I carefully plan out the worksheets and I make answer keys in advance to gauge timing and to anticipate student questions, but I don't write out much else.
Today, I wrote out a detailed lesson plan the way I used to, when I needed to turn in weekly lessons to supervisors or when I shared lessons with others. I wrote it out because I was being formally observed, so I wanted to be proper. But then, I misplaced it DURING the lesson!!! OMG I'm such an idiot. I tried not to look frantic but I really couldn't find it after putting it down somewhere. So, I decided to play it cool and just to keep going, obviously. (What we always do when lessons hit an unexpected turn.)
Naturally -- as these things always go -- I found the printed lesson plan immediately after class. It was under my stack of extra handouts the whole time. I had fully accomplished the aim, and the lesson had gone pretty well (the kids enjoyed and understood the algebra, and they helped each other as usual while I walked around to answer questions and to check in on the weaker students), but I had had to make up check-in questions on the spot since I couldn't find the "real" plan with the pre-thought of questions. sigh. Here is to hoping that my supervisor doesn't care that I didn't actually follow the plan to a tee.
PS. I used the exponent intro lesson for my formal evaluation. It worked very well; it didn't need much introduction but I did briefly introduce the handout by going through a couple of concrete numerical examples with the whole class, just to introduce/review relevant vocabulary words and to reinforce how to interpret the meaning of the coefficient vs. the exponent:
5*5*5 = 5^3 <--- 3 is the "exponent" or "index" (plural: "indices")
5*5*5 + 5*5*5 = 5^3 + 5^3 = 2*5^3 <--- 2 is the "coefficient", and this expression means we have "2 copies of 5^3"
x*x*x*x + x*x*x*x + x*x*x*x = 3*x^4 <--- "3 copies of x^4"
I would highly recommend using this (see link above) as a lesson for introducing exponent rules for the first time!! Kids were awesome and able to articulate the big ideas by the end of the 80 minute lesson. They were either primed for starting division of terms or had already finished that part off as well. Yesss.