Virtual Math Manipulatives

TechLearning recently (okay, back in October, but I've been busy ) featured an article about Teaching Mathematics with Virtual Manipulatives. Dr. Judy Donovan took the time to catalogue the best sites and although you could peruse the five page article online, I'll save you some time and paste the simple links here:

National Library of Virtual Manipulatives (My favorite, I use this extensively in my classes)
http://nlvm.usu.edu/

National Council of Teachers of Mathematics (searchable by grade!) http://illuminations.nctm.org/ActivitySearch.aspx

NCTM Electronic Examples Organized by Grade Level: http://standards.nctm.org/document/eexamples/index.htm

PBS Teacherline Math Interactives: http://www.pbs.org/teacherline/resources/interactives.cfm

Math Playground (all grades and levels)
http://www.mathplayground.com/

Fractions
http://math.rice.edu/~lanius/Patterns/

SELECT Math (Middle School Only) searchable by grade http://boston.k12.ma.us/teach/technology/select/

Money (Lower School)
http://arcytech.org/java/money/

Venn Diagram Shape Sorter (LS) http://www.shodor.org/interactivate/activities/ShapeSorter/?version=1.6.0_07&browser=MSIE&vendor=Sun_Microsystems_Inc.