Math

ConvertIt.com - Calculators for a variety of subjects, including measurement conversion, interest, distance, time zones, and currency.
http://www.convertit.com/

MathSite - Interactive exhibits include polygon dissection and stick sorting.
http://mathsite.math.berkeley.edu/

Math Forum: Student Center - Ask Dr. Math questions, or try your hand at the weekly puzzlers.
http://mathforum.org/students/

More Mathematics than Science - Learn how to use expressions to represent numbers, work with variables and create special drawings to represent equations. Also has a brief introduction to trigonometry and curve fitting. Includes interactive graphs.
http://id.mind.net/~zona/mmts/mmts.html

Plot the Robot - Activity site involving multiplication and calculator work. The answers are coordinates which can be joined in sequence to generate simple pictures.
http://www.jcutting.freeserve.co.uk/

Online Math Learning - Learn basic concepts behind arithmetic, algebra and geometry. Includes some SAT test preparation help and math trivia.
http://www.onlinemathlearning.com

Fugues of the Well-Tempered Clavier - Interactive Director movie comparing a fugue by Johann Sebastian Bach to a fractal.
http://jan.ucc.nau.edu/~tas3/wtc/i16.html

Coolmath4kids - Math games, problems, calculators, puzzles, and fun and for all levels.
http://www.coolmath4kids.com/

Math-Knowledge.com - Provides help in understanding math from the natural numbers to probability calculus.
http://www.math-knowledge.com

Maths on the Web - Collection of exercises and puzzles for all ages and abilities.
http://www.members.aol.com/ukhostmths/mathson/mathson.htm

Amazing Mathematical Object Factory - Offers tutorials on a variety of math topics including subsets, permutations, and Fibonacci sequences.
http://theory.cs.uvic.ca/~cos/amof/

Math for Morons Like Us - Covers concepts that are used in algebra and geometry, as well as an overview of calculus terms. Includes explanations on how to use the number line, working with formulas, fractions, square roots, graphs, parallel lines, triangles and areas. Also has a message board and short quizzes.
http://library.thinkquest.org/20991/home.html

mathmistakes.info - A selection of common mistakes made by students in algebra, trigonometry and calculus.
http://mathmistakes.info/

Kids' Place: Roz's Math-o-Rama - Features opinion polls, study tips, online math games, word problems, glossary, and interactive puzzles. Includes different sections for levels from kindergarten through the sixth grade.
http://www.eduplace.com/kids/mw/

Fact Monster - Math - Learn about numbers, measurement, money, tables and formulas. Includes conversion calculator, games and quizzes.
http://www.factmonster.com/mathmoney.html

Online Math Applications - Explains the role of math in investing, music, history, science, and travel. Includes stock simulation game.
http://library.thinkquest.org/4116/

GCSE Maths - Provides detailed descriptions of all the common subjects, concepts, and theorems, with examples and graphics to help explain the material.
http://www.gcse.com/maths/

Harcourt Math Glossary - Animated and illustrated definitions of math terms for elementary school students. Organized by grade level and alphabetically. [Requires Flash]
http://www.hbschool.com/glossary/math2/index_temp.html

MathStories.com: Word Problem Solving Strategies - Tips for solving word problems for K-5th graders.
http://www.mathstories.com/strategies.htm

Cynthia Lanius' Fractals Unit - Explains the unusual concept of partial dimensions and shows comparisons to a dot, line, plane and cube.
http://math.rice.edu/~lanius/fractals/dim.html

Math Worksheets - Features printable worksheets for students to practice with.
http://www.teach-nology.com/worksheets/math/

A Maths Dictionary for Kids - An animated, interactive math dictionary defining common math terms and concepts. [Requires Flash 5]
http://www.amathsdictionaryforkids.com/

Powers of Ten - Produced by Charles and Ray Eames, the video "Powers of Ten" has been converted into web images. Explores over 42 powers of ten in a series of images, beginning with a photo of someone lying on the grass. Shows the scale of the universe and atoms.
http://www.wordwizz.com/pwrsof10.htm

Math Goodies - Features interactive math lessons, homework help, worksheets, puzzles, message boards, and newsletters.
http://www.mathgoodies.com/

Mathwizz.com - Interactive worksheets and quizzes in basic math, pre-algebra, algebra, geometry, and statistics. Find calculators to compute interest and conversion tools for currency, area, temperature, and other units of measurement. Also runs a weekly math contest.
http://www.mathwizz.com

Interactive Mathematics - Online exercises through which children can explore and examine math concepts while at home.
http://nlvm.usu.edu/en/nav/grade_g_2.html

If You Are Good at Math - Provides information on the kinds of jobs available for kids interested in math.
http://www.bls.gov/k12/math.htm

Allmath.com - Features free flashcards, a magic square game, biographies of mathematicians, and other resources.
http://www.allmath.com/

Pi R Squared: Fractals - Explains the properties of fractal graphic images that can be created with special formulas. Also, introduces chaos theory and infinity. Offers free online help.
http://www.freewebs.com/pirsquared/fractals.htm

Ribbit's Math Ventures - Math problems that tell a story about a frog named Ribbit. For K-8.
http://www.mohonasen.org/staffdev/mathven/Ribbit/rdefault.htm

Math in Daily Life - Virtual exhibit looks at the ways people use math every day, from cooking to planning for retirement.
http://www.learner.org/interactives/dailymath/

The Abacus: The Art of Calculating with Beads - Introduces the abacus, relates its history, and shows how to perform basic mathematical operations on it. Also answers questions about the ancient tool and shows how to build one with Legos.
http://www.ee.ryerson.ca:8080/~elf/abacus/

Math.com - Offers free math lessons and homework help, with an emphasis on geometry, algebra, statistics, and calculus. Also provides calculators and games.
http://www.math.com/

Convertalot - A collection of free Java-based measurements converters, calculators, and unit translators.
http://www.convertalot.com/

Base 10 Blocks - Uses a visual computer program to teach the concepts of adding and multiplying in various mathematical bases. (Requires java.)
http://arcytech.org/java/b10blocks/

Math Flash - Free downloadable flash card game for children aimed at improving their mathematics skills with lessons aimed at various age groups.
http://www.huntingtonlearning.com/st-mathflash.php?

Maths Is Fun - Includes lessons, games, puzzles, and offline activities.
http://www.mathsisfun.com/

All Elementary Mathematics - An online mathematical high school. Arithmetic, algebra, geometry, trigonometry, functions and graphs, analysis. Theory and solving problems. Also has practice exams and math jokes.
http://www.bymath.com

Dositey.com - Interactive lessons and exercises, open-ended questions, printable worksheets, and challenging problems sorted by topic and grade range.
http://www.dositey.com/

Mathsforkids - This site has been created so that students can have fun and practice math. Includes lessons in addition, subtraction, multiplication, geometry.
http://www.mathsforkids.com/

Apples4theteacher.com - Offers games on counting, telling time, making change, measurement, and shapes.
http://www.apples4theteacher.com/math.html

Math Help: Exercises and Activities - Interactive activities and quizzes in basic arithmetic, algebra, and trigonometry. Also includes brain teasers and puzzles.
http://www.syvum.com/math/

Themathlab.com - A collection of educational math games and lessons for pre-algebra, algebra, and geometry. Includes practice problems and drills, a math dictionary, and a humor section.
http://www.themathlab.com

Richard Bowles' Math Tutorials - Learn about integers, positive and negative numbers, ratios, finding average values, statistical formulas, probability, simultaneous equations, quadratic functions and the binomial distribution.
http://members.tripod.com/~RichardBowles/maths/menu.htm

A+ Math - Helps students improve their math skills interactively with flashcards and games. Also provides worksheets and homework help.
http://www.aplusmath.com/

Teach R Kids Math - A large collection of interactive worksheets that allows kids to practice basic math skills.
http://www.teachrkids.com/

Word Problems For Kids - Have fun solving problems concerning rates, measurements, shapes, money, fractions and time. Page includes hints and solutions.
http://www.stfx.ca/special/mathproblems/

XP Math - Features a collection of math games, forum,and a list of jobs that need math.
http://www.xpmath.com