This is a favorite website of mine for finding just the perfect classroom activity!
FREE Teaching Resources for Your Classroom
I am writing to tell you about www.Curriki.org–a website for teachers that includes free access to over 32,000 K-12 high quality lessons, units, assessments and multimedia learning objects.
All of the resources on Curriki are contributed by teachers, universities, publishers and education professional development organizations from around the world. Furthermore, content is reviewed by subject-area experts and members to ensure quality.