Free Rice is a great site that has been in use since 2007. Your students can send rice to needy people while studying art, chemistry symbols, English grammar, geography, French, German, Italian, Spanish, basic math, multiplication tables or more. They even have a section for preparing for the SAT! Just click change subjects to choose a different topic.
The newest version allows you to change the language (that the directions are written, etc.) AND includes multiplication tables, capitals of the world, identifying countries from a map, and several other new topics!
This site does not require a login to use.