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The Protractor Tool

Let’s look for and make use of structure. Which of these is not like the other?

A. SMART Notebook software protractor tool

Screen Shot 2014-06-25 at 3.15.40 PM

B. Promethean ActivInspire software protractor tool

Screen Shot 2014-06-25 at 3.16.12 PM

C. PARCC digital tool

Screen Shot 2014-06-25 at 3.18.09 PM

D. Smarter Balanced digital tool

Screen Shot 2014-06-25 at 6.21.52 PM

If you were trying to attend to precision, would you prefer one over the other?

 

Question 26 on the PARCC EOY Grade 4 Practice Test asks which angle measures 65˚, which I can do without using the protractor.

Screen Shot 2014-06-25 at 6.31.27 PM

But I tried using the protractor tool, just to see how it worked, and I had a difficult time using it.

Screen Shot 2014-04-14 at 2.47.32 PM

It struck me that I don’t think using the protractor tool should be tricky. We are already asking students to measure while negotiating rotating the computer protractor with a mouse or trackpad. Do we expect them to guess where the rays would extend as well? On paper, I would use my pencil and a straightedge to extend the rays.

I felt confident about placing an initial ray of an angle at 0 using the other protractor tools.

Screen Shot 2014-06-25 at 6.22.07 PM Screen Shot 2014-04-16 at 5.58.12 AM

I’d be more confident about my precision using the PARCC protractor if there were a horizontal line connecting the 0/180 measurements on both sides.  But maybe there is a trick to using the PARCC protractor tool that I don’t know? Or maybe PARCC will consider improving their tool?

And so the journey continues, wanting the best tools available for our students so that they can show they know how to use appropriate tools strategically

 
3 Comments

Posted by on June 25, 2014 in Angles & Triangles, Geometry

 

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