White House for Kids http://www.whitehouse.gov/kids/whlife/index.html
National Geographic for Kids http://www.nationalgeographic.com/kids/
Test taking strategies and practice problems for math http://www.eduplace.com/kids/mhm/index.html
Math Test Prep http://studyzone.org/
Math Practice. This is great to practice place value. Math Practice
Quiz Hub--online interactive learning quizzes This is great to review geography, math, science, and fun topics! Quizzes for all subjects
Funbrain is a good site to practice math skills with a baseball twist. Good for drilling addition, subtraction, and multiplication! Fun Brain