Here are a few of my favorite sites:

http://www.k-3teacherresources.com/primary-school-maths-photo-gallery.html


www.thinkingblocks.com Great for Problem Solving

www.mathwire.com Great resource for all grades and topics

http://illuminations.nctm.org/ Loaded with activities, lessons, and links

www.nctm.org

www.daretodifferentiate.wikispaces.com Great resource for differentiation strategies

www.marylandmath.org

www.studyzone.org Great for test prep and review

www.teach.fcps.net Great resource for integrating technology into your lessons. Inlcudes templates for powerpoint games

www.firstinmath.com

www.mathbuddyonline.com Math Problem of the Day for grades 1-8

www.nlvm.usu.edu/en/nav/vlibrary.html virtual manipulatives website.