National Geographic.com Kids is a free service that has a large online database on science, nature, animals, history, cultures, maps, geography and art. The website isn’t grade level specific but there are articles, interactive tutorials and other resources that will benefit children in grades 3 to 12.

Students can search the database for any subject with the homework help search toolbar. The site also has a link to Xpeditions, a teacher’s resource page that parents can utilize; it provides lesson plans for specific subjects and grade levels.

National Geographic.com Kids does not provide contact information.

For a large homework help database that covers all subjects for all ages, see Cosmeo.