MATH TOOLS NEWSLETTER - OCTOBER 2, 2009 - No. 80

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  ***FEATURED ACTIVITY
  Activity: Printable compass / straightedge construction
    worksheets - Math Open Reference
  http://mathforum.org/mathtools/activity/87354/
  John Page
  A web page that contains a list of 35 printable worksheets
  for compass and straightedge constructions. Each printable
  sheet has 2 or 3 problems and links back to the pages
  interactively explaining the constructions needed. Each
  sheet has a space for student name.

  ***FEATURED ACTIVITY
  Activity: A Japanese Temple Problem
  http://mathforum.org/mathtools/activity/87146/
  Pat Ballew: Explorations in Geometry
  In this guided Geometer's Sketchpad exploration, students
  use their knowledge of tangent circles to discover a
  relationship between the radii of three circles which are
  mutually tangent to each other and an external line. This
  proof was drawn up on a wooden block and hung in a temple
  in Gunma prefecture of Japan in the early 1800's. The
  practice of hanging such proofs was called Sangaku.

  ***FEATURED ACTIVITY
  Activity: Math Operations in Lists
  http://mathforum.org/mathtools/activity/85103/
  Pat Ballew: TI-82 Users Guide
  These instructions detail mathematical operations that can
  be used on lists or sequences of numbers with the TI-82.
  They include questions to test students' understanding,
  with answers at the bottom of the page.

  ***FEATURED TOOL
  Tool: Function Grapher Online
  http://mathforum.org/mathtools/tool/83600/
  Amir Rashedi
  Graph functions and find roots (zeros) of functions without
  guesswork. Specify domain for functions, drag the graphs
  and rotate the axes.

  ***FEATURED TOOL
  Tool: Abacus v1.4
  http://mathforum.org/mathtools/tool/80580/
  Dana M. Proctor
  The Abacus Java Applet/Application is an implementation of
  an Abacus counting machine. The machine displays a total
  for the number represented by the machine's current state
  in addition to each digits value. The program provides a
  learning tool to teach basic concepts of the base 10
  counting system.

  ***FEATURED TOOL
  Tool: Paramertic Surfaces in Rectangular Coordinates
  http://mathforum.org/mathtools/tool/83946/
  Barbara Kaskosz and Doug Ensley
  This 3D grapher graphs a parametric surface defined in 
  rectangular coordinates. The user enters parametric 
  formulas for the x, y, and z coordinates and the applet 
  draws the corresponding surface in 3D. The surface can be 
  rotated in real time by the user with the mouse and its 
  opacity can be changed. The second version of the grapher 
  is much older and slower as it is written in AS1, but it 
  has a few practice problems that might be of interest.

  ***FEATURED TOOL
  Tool: The Abacus in Various Number Systems
  http://mathforum.org/mathtools/tool/81628/
  Alexander Bogomolny
  An interactive Java applet showing one or two Russian
  abacuses with options to select the base of the number
  system and the number of wires. The applet displays the
  number matching the current configuration and performs
  an automatic carry. The abaci can be synchronized so that
  adding to one removes an equal number from the other.
  Bogomolny links to a page discussing the history and use
  of the abacus.

  ***FEATURED TOOL
  Tool: Suan Pan in Various Number Systems
  http://mathforum.org/mathtools/tool/81629/
  Alexander Bogomolny
  An interactive Java gadget simulating suan pan -- the Chinese
  abacus. Options include selecting the number system base
  and the number of wires. The applet displays the number
  matching the configuration and performs an automatic carry.

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    The Math Forum @ Drexel -- 2 October 2009