Tuesday, November 28, 2017

Teach 180: Informal before Formal (Day 58)

Two years ago I created my very first Desmos Activity Builder lesson.  It was called "What is the Derivative, Anyway?"  This year I am teaching Calculus again and I was able to pull out this Desmos AB lesson to use in class today.  As I was reviewing it last night, I noticed several things that I think make this a good introductory AB lesson.

First, students are set up to be successful.  They have the foundation needed to do the lesson based on what they learned in our previous chapter.  And since we just had Thanksgiving break, it was a gentle way to get them thinking about math again.  Plus, I could easily use the teacher dashboard to identify student pairs who had "off" answers.  (One pair said "No" to a question that was not a "Yes/No" question and I was able to visit them for a quick discussion.)

Second, the screens build off of each other.  For example,  students are asked about intervals where the tangent lines have positive slopes and then are asked about intervals where the tangent lines have negative slopes.

Third, it introduces vocabulary after students have had a chance to informally describe a concept for themselves.  On the screen below, students are asked "or is something else going on"?  Some students simply answered this with one word "constant" or horizontal".  Jack and Grayson said "there is a horizontal tangent, therefore the function is at a peak or valley".  To encourage more of a description of what is going on, I'm going to modify the directions on this slide slightly for future use. The informal idea of a peak or valley lead to formally talking about relative maximums and relative minimums.

After we get through much of this current unit, I am hoping to create a Talkers and Drawers activity, like what is described by Job Orr in his blog post "Three New Desmos Activities: Talkers and Drawers".   I'll probably use it as a way to review concepts before our test in a few weeks, but it might also be a good activity to do as we ease back into things after Christmas break.