This site provides a description of "dark matter" and how scientists study it. Vocabulary words linked to a glossary of terms, and a printable version are also available on the site.

This site has a description on what you need to do to become an astronaut. Learn about astronaut training and assignments. Vocabulary words linked to a glossary of terms. Printable version available.

Each term of Intermath's interactive math dictionary contains a description and links to related terms, everyday examples, interactive checkpoint, more information, and challenges located in the left-hand column of the page. This...