Great site to help you with all your math problems. http://www.AAAmath.com/
FunBrain--fun and games http://www.funbrain.com/kidscenter.html
Games and practice sheets/flash cards http://www.aplusmath.com
Visual Fractions--a visual way to compare, add, and subtract fractions http://www.visualfractions.com/
Another fraction site http://www.coolmath4kids.com/fractions/
http://www.mathplayground.com
Mind benders--some challenging ones! http://www.syvum.com/teasers/
Here's a little magic trick for you. Can you figure out how it works? http://kids.niehs.nih.gov/mindread/psychicSparkle2.swf
Great all purpose site http://rozauer.tripod.com/elemmath.htm
Adding and subtracting integers http://www.math.com/school/subject1/lessons/S1U1L11DP.html
Subtracting integers http://www.mathwizz.com/integers/page3.htm
Good practice for Everyday Math http://www.math.com/practice/EverydayMath.html
Great general purpose 6th grade site http://www.learnalberta.ca/content/mesg/html/math6web/math6shell.html
Great interactive site--Parallel lines and a transversal http://www.mathwarehouse.com/geometry/angle/interactive-transveral-angles.php
Another interactive site--Parallelograms http://www.mathwarehouse.com/geometry/quadrilaterals/parallelograms/interactive-parallelogram.php
Interactive ordered pairs http://www.mathwarehouse.com/ordered-pairs/interactive-ordereded-pairs.html
Plotting points game http://www.oswego.org/ocsd-web/games/BillyBug2/bug2.html
Logic Puzzles http://www.puzzlersparadise.com/page1034.html
Adjustable Spinner http://illuminations.nctm.org/ActivityDetail.aspx?ID=79
Lots o' fun with gigantic numbers. Click on the link at the bottom of the page for the penny activity. http://www.mathcats.com/explore/reallybignumbers.html
Playing with powers of 10 and orders of magnitude: From the Milky Way to the quark http://micro.magnet.fsu.edu/primer/java/scienceopticsu/powersof10/