National Library of Virtual Manipulatives
http://nlvm.usu.edu/en/nav/vlibrary.html

NCTM Illuminations
http://illuminations.nctm.org/

AAA Math
http://www.aaamath.com

ArithmAttack
http://www.dep.anl.gov/aattack.htm

Cool Math
http://www.coolmath.com/

Create a Graph
http://nces.ed.gov/nceskids/createagraph/default.aspx

Learning Planet
http://www.learningplanet.com/stu/kids0.asp

Ask Dr. Math

http://mathforum.org/dr.math/dr-math.html

Kathy Schrock’s Guide for Educators – Math

http://school.discoveryeducation.com/schrockguide/math.html

Interactive Math Activities

http://www.cut-the-knot.org/Curriculum/index.shtml

Internet 4 Classrooms (I4C)

http://www.internet4classrooms.com/math.htm

A Plus Math

http://www.aplusmath.com/

Interactive Math Games/activities
http://www.sheppardsoftware.com/math.htm