# Class Opener – Day 39 – It’s a Heat (Map) Wave!

Finishing up discussions with scatterplots – today’s visual when students entered presented a new idea in scatterplots (from the awesome Plot.ly site) – a scatterplot representing the score of every NFL game ever played!

What’s the story here? So many great features of this plot to discuss including:

• It’s apparent symmetry
• The vertical and horizontal avoidance lines
• The colors – many students have never seen a heat map before
• The clustering in the center of the graph

This was a quick warm up as I wanted to get to the main event – scatterplot stations!  Students worked in teams to complete activities (in 15-minute intervals) designed to strengthen their understanding of many ideas surrounding scatterplots.

Station 1 – using graphing calculators to assess data sets, and writing clear summaries of the trends.

Station 2 – estimating best-fit lines given a scatterplot, and using their algebra skills to make good estimates.

Station 3 – netbooks! Play with the Rossman-Chance “Guess the Correlation Applet” and develop and understanding of “least squares” with this Geogebra applet.

Fun day today…..moving on to sampling tomorrow!