2012-11-27

Mathematical tools – Part 2

Were it not for convoluted language, plenty of lawyers would be out of work.  Educators, though, shouldn't be subjected to such torture.

William McCallum, one of CCSSI’s authors, wrote in the comments section of an article appearing on The Atlantic Magazine website, written by Barry Garelick, ``I agree with you that there is a lot of misreading of the standards out there in the field, and this is a problem.’’  Such arrogance.  The real problem is that CCSSI is poorly written, not only substantively, but also in its lack of clarity.

7.G.2’s ``Focus on constructing triangles from three measures of angles or sides...‘’ is at best, ambiguous.  Writing intelligible English is not the same as constructing logic gates, where the definition of ``or’’ invariably includes the possibility of both.  The parallelism in the sentence implies you are given either 3 angles or 3 sides, but we suspect it’s supposed to mean the following: ``Focus on constructing triangles given various combinations of three angles and/or sides.’’

2012-11-12

Mathematical tools – Part 1

CCSSI 7.G.2 states, ``Draw (freehand, with ruler and protractor, and with technology) geometric shapes with given conditions. Focus on constructing triangles from three measures of angles or sides, noticing when the conditions determine a unique triangle, more than one triangle, or no triangle.’’

Some preliminaries before we parse this standard.

Protractors


We here at ccssimath.blogspot.com LOVE protractors.  The way we see it, a (non-toxic, teething) protractor should be given to every newborn in their bassinet (thanks to Charles Schulz for the inspiration); perhaps the first one can be hanging from a mobile.  A protractor (like a banjo) is a happy thing: it’s a smile, or a big letter D.  A protractor is easy to hold, it’s too big to choke on, and it’s covered with numbers.  It even has mystery and intrigue, for why would the numbers run in opposite directions?  Rulers, in contrast, though useful, are dangerous things; they fit in the mouth and can be brandished as swords.