National Geographic for Kids http://www.nationalgeographic.com/kids/
Brain Boosters for Kids http://school.discovery.com/brainboosters/
White House for Kids http://www.whitehouse.gov/kids/whlife/index.html
States and Capitals http://www.vectorkids.com/maps.htm
Math Fact Cafe Grade specific as well as creates flash cards, practice sheets, time practice........... http://www.mathfactcafe.com
Math Games-The hidden pictures are good............. http://www.aplusmath.com/games
Place value...standard notation http://www.aaamath.com/B/g21e_px1.htm
Cyber Challenge http://www.mathmastery.com/cyberchallenge
Go down to Fact Dash.........great fact drill http://www.mhschool.com/math/2002/student/3/index.html
Spelling City...Great Study tool for spelling tests http://www.spellingcity.com/
Math Facts http://www.coolmath4kids.com/
Math Facts http://www.mathmastery.com/cyberchallenge/