Monday, October 21, 2013

Day 40: Intro to Absolute Value

I wish I had taken a picture of our human graph!  I gave several students pictures of buildings.  They had addresses.  They lined up.  One building was the fire station.  Students on either side of the fire station stepped forward the number of blocks they were located from that reference point.  Voila!  Our human graph.  Students watching the process yelled out it's absolute value, it's quadratic ... and so the discussion began for the day.

The rest of the lesson was built around estimating the number of candy corn candies in the bag - from Estimation 180.  (Parents sent in individual packs of candy corn for us to enjoy as we worked through our exploration.)  I wrote about my plans here and here.

First we made our own guesses ... how many scoops fill the jar.  This time, I asked students to share their reasoning before I revealed the solution.  I also shared my reasoning.  I stressed to students that blindly guessing without some point of reference was not the point of the task.

Then I revealed the data from the email I sent to staff, parents, and select students the week before about how many candies were in the bag of candy corn.

Students worked through the analysis of the data using Google spreadsheet, their graphing calculator and Desmos.  (Yes, the technology was overkill, but I was trying to help students see that each tool has its own benefits ... and they need to know how to use all three!).

The emphasis was on noting the two linear functions that formed the absolute value equation, the restriction on the domain and range, and the relationship between the data and the functions.

The day went OK.  To be honest ... I had more fun planning the lesson than implementing the lesson.  So tonight it's all a bit ho hummm!

**Plan originated with help from Kate at http://function-of-time.blogspot.com/;  she published three awesome blogs on absolute value.

1 comment:

I'm glad that Estimation 180 could play a part in your lesson. I hear ya on the fun-level being greater during the planning stages that the implementation. I've been there.

I love this, "blindly guessing without some point of reference was not the point of the task." Keep up the good work. By the way, thanks for the heads up on "scoops" versus "cups." The site has been updated.