6th Grade - Course I practice site http://www.phschool.com/webcodes10/index.cfm?fuseaction=home.gotoWebCode&wcprefix=aak&wcsuffix=0099
ask dr. math http://mathforum.org/library/drmath/view/58042.html
aaa math http://www.aaamath.com
A+ math http://www.aplusmath.com
Prealgebra text book site http://www.phschool.com/webcodes10/index.cfm?fuseaction=home.gotoWebCode&wcprefix=adk&wcsuffix=0099
Math practice equations for 6th http://www.ixl.com/math/grade/sixth/
Calculation Nation from NCTM http://calculationnation.nctm.org/Games/