Activity and Game Sites for Students:
A little of this, a little of that... interactive math sites for students:
Online Graph Tool: http://nces.ed.gov/nceskids/createagraph/default.aspx
Online Collection of Student activities: http://www.bbc.co.uk/schools/websites/4_11/site/numeracy.shtml
Online Interactive Math Resources: http://www.woodlands-junior.kent.sch.uk/maths/
More Math "games": http://gamequarium.com/math.htm
Math Cats: http://www.mathcats.com/index.html#contents
Good for IWB: http://www.crickweb.co.uk/ks2numeracy.html
A collection: http://www.tusd1.org/resources/math/all-el.asp
Best for Young Mathematicians:
http://www.mathcats.com/explore/polygonplayground.html
Online Graph Tool: http://nces.ed.gov/nceskids/createagraph/default.aspx