MATH TOOLS NEWSLETTER - OCTOBER 2, 2009 - No. 80 As you browse the catalog, please take a moment to rate a resource, comment on it, review it -- join an existing conversation, or start a new discussion! ***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. CHECK OUT THE MATH TOOLS SITE: Math Tools http://mathforum.org/mathtools/ Register http://mathforum.org/mathtools/register.html Discussions http://mathforum.org/mathtools/discuss.html Research Area http://mathforum.org/mathtools/research/ Developers Area http://mathforum.org/mathtools/developers/ Newsletter Archive http://mathforum.org/mathtools/newsletter/ \`. .--------------.___________) \ |//////////////|___________[ ] `--------------' ) ( The Math Forum @ Drexel -- 2 October 2009