Check out these Websites for more practice of essential math skills:
(copy and paste in browser)

National Library of Virtual Manipulatives

http://nlvm.usu.edu/en/nav/vlibrary.html

Games

http://www.sheppardsoftware.com/math.htm
http://www.gamequarium.com/math.htm
http://www.coolmath-games.com/
http://www.funbrain.com/kidscenter.html

Multiplication Practice

http://www.multiplication.com/interactive_games.htm

Everyday Math

http://www1.center.k12.mo.us/edTech/everydaymath.htm