This professional development video clip shows students engaged in the Common Core Practice Standard #3-Construct viable arguments for conclusions reached and critique the reasoning of others. Students work with geoboards to explore the concept of "halves" which requires them to explain their reasoning and justify their findings to their classmates. Additional resources include a video transcript, teaching tips, and a link to a professional development reflection activity based upon the video. A related clip (cataloged separately) shows the same exploration by the same students but the video is focused on Common Core Practice Standard #6—Attend to precision is evident.


  • Mathematics > General
  • Education > General

Education Levels:

  • Grade 1
  • Grade 2
  • Grade 3
  • Grade 4
  • Grade 5
  • Grade 6
  • Grade 7
  • Grade 8
  • Grade 9
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  • Grade 11
  • Grade 12


Visualization,NSDL,Grade 4,Area,Critical thinking,oai:nsdl.org:2200/20140728160928897T,Quadrilaterals,Visual representation,Mathematics,Number concepts,Arithmetic,Fractions,Connections,Number and operations,Upper Elementary,Mathematical language,Grade 5,Teaching strategies,Vocational/Professional Development Education,Area of polygons,Concept formation,Whole numbers,Problem solving,NSDL_SetSpec_ncs-NSDL-COLLECTION-000-003-112-027,Geometry,Practice Standards,Reasoning,Representation,Communication,Systems of measurement,Number sense,Congruence,Polygons,Plane geometry,Elementary School,Grade 3,Critique reasoning,Measurement,Process skills,Education,Construct arguments,Nonstandard



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