Published by the National Council of Teachers of Mathematics (US)
The geoboard used in the activities on this site illustrates how a “virtual” classroom manipulative can sometimes have advantages over its physical counterpart. In this case, the capacity to use colour helps students to compare the features of the variety of triangles and other polygons they can create using interactive geoboards. This activity is just one from the National Council of Teachers of Mathematics (NCTM)’s excellent E-examples collection - click on “E-examples” in the menu to see the others. Suitable for early primary students.
Published by Alexander Bogomolny (CTK Software, Inc)
This page is sure to give you some new ideas for exploring Pythagoras’ Theorem, using both concrete materials and some great computer-based illustrations. Activities consist of 72 approaches to proving the theorem and associated Internet links. Some are presented with static diagrams, while others use interactive Java applets. You can also follow the “Front Page” link in the left menu for access to other elements of the parent “Interactive Mathematics Miscellany and Puzzles” site. Suitable for secondary students and beyond.
Published by The Shodor Education Foundation, Inc. (US)
This site allows users to create their own unique tessellations online. Students can modify a triangle, rectangle or hexagon by altering the sides to make their own tessellating polygon. They can then experiment with the effect on their pattern of changing colours or editing the shape, and then print their creations! Instructions, background information and access to related resources are readily available for teachers. Links from these pages will also take you to the extensive array of other activities available from Project Interactivate. Suitable for middle primary and beyond.