The Prime Pages - Chris Caldwell
A View from the Back of the Envelope - Mitchell N. Charity
A trove of pages about approximation. The site talks about: measuring length, distance, and angles with your body; orders of magnitude; ways to use analogies and examples to visualize how big things are; methods for simplifying numbers; explorations of exponential notation; rough estimates of real-world quantities; developing "deep" understanding; and getting a feel for big numbers (with examples such as picturing altitude above maps). Includes a web copy of the 1957 book Cosmic View: The Universe in 40 Jumps, which inspired the film Powers of Ten.
Erich's Packing Center - Erich Friedman
Imagine three or more equilateral triangles, each with side length 1. What's the smallest square they all fit into without overlap? Find the answer at Erich's Packing Center, along with numerous two- and three-dimensional packings, coverings, tilings, packings with unusual constraints (rigidity, polyomino shapes), and related problems (tree planting, triangulating, shapes touching n others, and the Heilbronn problem).
EggMath - Bradlow, Sullivan, Levy, and Klamik
Welcome spring with this egg- and chick-themed flock of classroom modules. Java applets illustrate: the shape of an egg (symmetry and cross-sections, surfaces of revolution, pin and string construction of ellipses, and Cartesian and Cassini Ovals); the White/Yolk (or Ham Sandwich) Theorem (how any region of the plane can be divided into two equal parts--a special case of the Borsuk-Ulam Theorem); spherical geometry (the intrinsic curvature of a spherical surface); and embryo calculus (exponential growth, tangents and slopes, and the number e). Download EggMath pages and applets for standalone use on Macs, Windows, and UNIX machines. EggMath is part of the Chickscope Project at the University of Illinois at Urbana-Champaign.
Building Big - WGBH Educational Foundation
Apply your math skills as you explore the challenges of engineering. Learn about bridges, domes, skyscrapers, dams, and tunnels; experiment with forces, materials, loads, and shapes in Flash interactive labs; test your structural knowledge with interactive challenges; investigate big structures through the Wonders of the World Databank; report on big structures near you; and discover what real engineers love about their jobs. The Educator's Guide offers hands-on activities and classroom tips. Based on a five-part PBS television series from WGBH Boston hosted by author-illustrator David Macaulay--fans will enjoy reading a chat with Macaulay as well.
Gallery of Data Visualization - Michael Friendly, York University, Canada
The Best and Worst in Statistical Graphics on the Web: Examples of both the most elegant and informative visual presentations of information and the worst cases of lying with graphs. Also includes historical milestones and innovations in graphing techniques.
Thinking Fountain Shapes Cluster - Science Museum of Minnesota
Investigate which shape makes a stronger or taller structure, go on a shape walk, play with soap bubble geometry, and more. These hands-on experiments and activities relate shapes to elementary math, science, and language arts. Each page lists related activities or resources, including recommended books about shapes. Don't miss the museum's other theme clusters, such as tropical rainforests, air, the Journey North (monarch butterfly migration), and students as designers.
Spy Guys: Online Elementary Mathematics Resource -- Mathematics 6 - Alberta Learning / LearnAlberta.ca
Learn 6th-grade mathematics with Flash 5 animations: interactive lessons (including activities and mini-quizzes); problem-solving strategies; number operations (how to learn math facts); glossary of math terms; printable activity sheets; and printable tips for parents to reinforce learning at home. Developed by Alberta Learning with the help of Alberta teachers.
Math Tools - The Math Forum at Drexel
A library of software tools for teaching and learning mathematics, including applets or programs that run on computers, calculators, PDAs, and other handheld devices. With the library's organization, you can review, discuss, and share classroom activities; examine research; and encourage new software for a number of platforms. Currently the best-stocked areas are the Math 2, Math 7, and Pre-Calculus levels, but the site is growing to encompass pre-kindergarten through calculus. Free registration gives you membership benefits such as a monthly newsletter detailing new features.
Count Us In! - Learn Online, Australian Broadcasting Corporation
Simple, appealing Flash 5 games to help young children learn number concepts, including counting, addition and subtraction, patterns, chance, time, and measurement. The section of Other Activities offers lesson ideas for the classroom. Games may be downloaded for use offline on Macs and PCs.
StudyWorks! Online - MathSoft, Inc.
Broaden high-school-level math and science skills with these rich, engaging, Java-based "explorations" of the world around us. The site also includes games and puzzles, math and science news items, and a discussion board for homework help. Science fans, be sure to check out the Physics Classroom.
Create Your Own Interactive Games - Cathleen J. Chamberlain and Mark Cogan, Oswego City School District
Try out pre-made games in a range of math topics at elementary school levels, or make your own matching games or multiple-choice quizzes. Matching games may be made using words, phrases, or graphics, using typing or drag-and-drop interfaces. Don't miss the Oswego City School District's interactive Test Prep sites, at the Elementary (4th grade), Middle School (8th grade), or Regents (for high school graduation) levels.