http://www.aaamath.com/
http://www.mathplayground.com/
http://www.ixl.com/ (can join for a fee or complete 20 problems a day for free)
http://www.homeschoolmath.net/ (great place to print worksheets)
http://www.tlsbooks.com/
http://www.superteacherworksheets.com/
http://www.tooter4kids.com/
http://www.brainpop.com/
http://www.starfall.com/ (great for the little brothers and sisters of my 5th graders, learning to read!)
http://www.funbrain.com/
http://www.coolmath4kids.com/
And Mrs. Lewter's personal favorite...
http://www.storybird.com/ (You can write and illustrate your own stories!)
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