It seems to be the season to teach MAD - Mean Absolute Deviation. I have taught it in the past, but boring and dry.
I saw Tom Hall's post on twitter with his lesson using Estimation 180.
He linked to Nathan Kraft's post.
I liked both but then I remembered NCTM Boston from Spring 2015 and they used famous people's ages.
I don't remember who taught the lesson but it was called A-E-I-O-U - Algebraic Enriching Opportunities for U. It had a lot of great hits on Alg 1 stuff. I used their powerpoint with 20 people but I removed one and added our principal. They have to guess the people's ages. Then, I will reveal their real age and we will discuss MAD via this. I think the kids will like it and hopefully remember why we would do this in the first place.
Short post, but no time after school. We have Relay for Life after school through the night.