• SodaPlay
• How Stuff Works
• Quia Science - K-12 science games
• Molecule of the Month
• Nine Planets
• Your Weight on Other Worlds
• The Exploratorium Observatory
• National Space Science Data Center Photo Gallery
• Astronomy Picture of the Day
• Quia Astronomy - K-12 astronomy games
• WebElements
• Quia Math - K-12 math practice 
• WebMath
• US Government Time Page
• Calendars Through the Ages
• Quia Biology - K-12 biology practice

Also click on the math & science topics at SparkNotes and at Refdesk.com

And try the Indispensable sites and Homework section at Refdesk.com

Last Updated: 05/23/2011