Here are a few websites for Math practice: http://www.brainpop.com/math/
Several classroom teachers use brainpop.com for not only Math, but Science too! They really like the way the activities engage the learner.
On-Line Mathematics Manipulatives http://oneweb.utc.edu/~deborah-mcallister/onlinemath.html
Run by the University of Tennessee, this site provides an index of other website providing manipulatives as well as links to specific activities. Topics include pattern blocks, flash cards, and algebra tiles.
