http://www.enchantedmind.com - This site has creative Java puzzles designed to exercise both sides of the brain. The site includes a puzzle link, which connects to a hands-on tangram activity, pentomino activity and chess.
http://math.rice.edu/~lanius/Lessons/ - This site has numerous hands-on math-related activities to include graphing, algebra, geometry, calculus, polyominoes (dominoes/ tetrominoes), ratios, applied mathematics as well as fractions using pattern blocks.
http://www.best.com/~ejad/java - This site has links to three math-related activities: base-ten blocks (whole decimals, place value and algebra), pattern blocks (fractions) and Cuisenaire (Integer) rods (math skills, fractions, decimals).
http://www.funbrain.com - This site has many educational activities for a wide age range. Math activities include math baseball, football, soccer, racecars, money (change making, checkbook), fractions, graphing, patterns, measurement, and surveying.
http://www.quia.com/dir/math/ - This site includes a matching game format for students to reinforce various skills such as equivalent fractions, addition, multiplication, division, fractions/decimals, geometry, angles, algebra, trigonometry, measurement, square roots, and change making.
http://forum.swarthmore.edu/students - This site will link students to Ask Dr. Math where they can ask any math-related question or they can view the Math Tips & Tricks for insight on techniques to sharpen their skills.
http://www.mathgoodies.com - This site includes interactive math lessons, which include statistics, pre-algebra, probability, percents, area and perimeter.
http://www.aaamath.com - This site covers all grade level and all math topics to include basic math skills, decimals, geometry, estimation, graphs, patterns, and place value. Includes interactive lessons, explanations, and challenging math games.
www.mathstories.com - This site is geared for elementary and middle schools. It focuses on math problem solving and critical-thinking skills. Grade level problems are grouped by topics such as division, estimation, fractions and time/rate.