Great Math Websites   

www.coolmath4kids.com Great for all grade levels. Instruction and practice games.
www.aplusmath.com Teacher resources as well as practice games for students.
www.primarygames.com Includes activities for math, science, and social studies. Good for all grade levels.
www.playkidsgames.com Vocabulary component for 1st - 4th grade.
www.mathplayground.com Good for 3rd and 4th grade. Also includes practice sheets for teachers to produce.
www.counton.org/games/ Great "Mathanaire" game that would be great for the whole class using Promethean board.
www.mrnussbaum.com Also includes language arts, science, and social studies activities
http://www.iknowthat.com/com/GradeLevel?GradeLevel=999&Subject=Math Math activities for all ages. When asked for login just click on "Maybe later" button on lower right.
http://www.figurethis.org/index.html Figure this! developed by the national Council of Teachers of Mathematics and provides weekly math challenges. Material is also available in Spanish.
http://www.umsl.edu/~wpockets/clubhouse/clubhouse.html A koala named Wise Pockets helps kids with saving, spending, earning cash, and other financial matters.
   
Be sure to check your computer for the necessary plugin programs needed to play the games.