Below are links to several helpful maths web sites that provide fun, interesting maths games to play or concepts to revise. Some of these are used in school, however they are expanding and changing all the time and parents are advised to keep a check on the sites themselves. They shouldn't contain inappropriate content or links, but no web site is ever completely reliable!
ixl.com (An extensive web site that looks slightly more 'schoolish' but is broken down into year groups and then into different maths topic areas, so would be helpful for finding an area for revision quickly.)