Tuesday, January 16, 2018

Teaching Geometry - Expected Value

I am teaching a new prep this year - Accelerated Geometry, along with Acc Alg 1 and Acc Alg 2.  It is a lot.  I have taught a lower level Geometry course, but a while ago.  I have a colleague who also teaches it, so I have the quizzes (I make different versions). I have the homework.  (I still do each problem).  I have the Do Nows, but have to do them.  And, then of course there is the presentation - the lessons, those are mine and how I run the class.  I have the what and when, but I get to create the how and I enjoy the creation part.

This is where expected value comes in.  I have not taught it before.  I'm not even sure I learned it before.  So, I immersed myself in it. I went down the EV rabbit hole, reaching, researching, reading definitions, real life uses for it, formulas, worksheets, examples.  We have a target example in the book I knew I was going to use but I thought it might not be a good starting point.

It has the whole area of a circle and the probability of hitting each ring.  I was teaching probability so it should be okay, but I didn't want them to enter at that point and get hung up.  I am all for starting with a challenging problem, but today's lesson was not it.

I also am doing a lot of VNPS - having the kids work at the whiteboards to discover Geometry.  I knew I would be teaching this lesson on the first day back from winter break, so I wanted to have them up and working and discussing, but I just couldn't do it.  I didn't want to force it.  It just didn't fit with that kind of lesson and that is okay.  I felt this topic had to be a whole class, step by step procedure.  That doesn't mean it had to be boring.  I just wanted to slow it down a little and take it one piece at a time.  I also decided to start at a carnival with a card game.  A standard deck of cards because we were familiar with the probability in a deck of cards.

I started like this:

I got them interested.  Some had questions - what do we win?  (I was going for 3Act style, not giving away all the information.)