The following websites have interesting online interactive games that can support your child's learning.
http://www.kidsknowit.com/ This website has free math games, spelling games and other interesting subject areas.
http://www.funbrain.com/ This website has online educational games for kids of all ages (math, grammar, science, spelling, history).
http://www.stuff.co.nz/technology/gadgets/gadget-reviews/632374/Guide-to-educational-websites This article from stuff.co.nz has links to a range of websites that are both educational and fun.