Our third edition of Homeschool Freebies will feature math and science.
MEP is a completely free math program being used in the UK. If you are interested, I highly recommend checking out this group, who can answer any questions you may have. Awesome program, full of puzzles and lots of mental math.
This site has free online activities for all grades from preschool to middle school. Since my kids love to play on the computer, this has been a hit.
And here is a site with lots of links to other sites with free math resources. A link to links.. hope you've got some time! :)
Inquiry in Action offers a free, downloadable chemistry curriculum for the lower grades. All experiments can be done with household items.
This site also offers free curriculum, in many areas of science, for all grades.
Here is another option for free science curriculum.
Honestly, my favorite resource for science are Bill Nye videos. Most libraries have them, ours has about 40. Watch the video, do the experiment they show during the 'do this at home' section, and make an experiment page. Easy and free. My kids ask to bring the videos home for fun!
Hope that helps! Feel free to link up your favorite free math and science resources by leaving a comment.