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  • Domain & Range Stand & Talk

    Posted by Mary Manske on January 28, 2020 at 6:07 pm

    I’m writing a Stand & Talk for my Algebra 1 students about domain and range. We talked briefly about domain in terms of the number line before but they are not familiar with range. This would be the first thing we do with domain & range, and I can’t decide what it should include. 

    Ultimately I want them to know:

    -inequality and interval notation for writing domain & range

    -domain as x/input/independent and range as a y/etc (only the first is here)

    -how to identify domain & range

    1. The sketch below includes both a discrete and continuous function (should I only do continuous? 2 continuous and no discrete?). It also includes a lot of representations–probably too many. 

    2. We considered some kind of shading or boundary lines but can’t decide what to do. I like the idea of shading, but I would probably shade OUTSIDE not inside (like graying the rest so we can focus on the region of interest). That contradicts inequalities but otherwise it could be hard to see? Use dashed lines to isolate the region?

    3. Do I include multiple notations?

    They will notice & wonder silently and then with a partner, then we’ll debrief. Ideally as many goals as possible should come out from the notice & wonder, and then we’ll consolidate. If I throw too much at it though, it can obscure the connections I’m hoping they’ll make. Ideas about what to include?

    Jon replied 3 years, 1 month ago 2 Members · 1 Reply
  • 1 Reply
  • Jon

    January 30, 2020 at 6:09 pm

    Hey @mary-manske 

    You’ve got some great ideas here….I think more representations is better than one at time….it will reinforce the connection between graphical and numerical. 

    Have a look at Desmos’ activities on domain and range 

    Let me know what you think.