Share 'Math Classroom Resources - Online or Offline'

I would love to know what websites, resources or manipulatives you find useful in your classroom. Some that I find helpful are: Online: www.Gapminder.org is a website with a lot of world statistics. I use to demostrate graphs, line of best fit, correlation coefficient, and stats. www.ExploreLearning.com has a large collection of visually and interactive demostrations of math and science concep…