This webpage contains a link to a downloadable Geometer's Sketchpad activity that familiarizes students with inequality signs (> and <) and introduces the use of the variable x to represent an unknown value. Students are challenged to deduce a number by collecting and analyzing clues that narrow its range of possible values in the fewest guesses. The page also includes a three-minute instructional video and downloadable PDFs of teacher notes and student worksheets. This activity opens on Geometer's Sketchpad as well as on iOS with Sketchbook Explorer (cataloged separately).


  • Mathematics > General
  • Education > General

Education Levels:

  • Grade 1
  • Grade 2
  • Grade 3
  • Grade 4
  • Grade 5
  • Grade 6
  • Grade 7
  • Grade 8
  • Grade 9
  • Grade 10
  • Grade 11
  • Grade 12


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