http://www.ed.gov/pubs/EarlyMath/whatis.html This web site was designed by the National Council of Teachers of Mathematics and focuses attention on children's early lives before they enter school.
http://illuminations.nctm.org/swr/index.asp This site is part of the National Council of Teachers of Mathematics web site called "Illuminations". It provides parents and teachers with a dynamic menu to selectively search over 1100 carefully reviewed Internet math resources. Parents can find material to assist children who might not understand a particular math concept, as well as materials that will extend children's understanding. The site also provides parents with an increased appreciation of how the teaching and learning of mathematics has changed.
http://www.eworkshop.on.ca/ eWorkshop has been created by the Ministry of Education and its development partner, TVOntario. The site is aimed at supporting effective reading and math instruction in elementary schools across the province. It is an excellent site for parents to see how mathematics is being taught in Ontario's schools, and provides many ideas for helping children at home. There is both French and English language access.
http://www.mathcats.com Mathcats contains a wide selection of open-ended math explorations for many age groups. The Site Map has an easy to follow menu of many excellent activities.
http://www.figurethis.org/index.htm Figure This! provides interesting math challenges that middle-school students can do at home with their families. It was developed by the National Council of Teachers of Mathematics and funded by the National Science Foundation (USA) and the U.S. Department of Education.
http://www.ed.gov/pubs/parents/Math/ Helping Your Child Learn Math provides proven ideas and activities for families to help their children succeed in math. It is funded by the U.S. Department of Education.
http://mathforum.org/dr.math/dr-math.htmlAsk Dr Math is a question and answer service for math students and their teachers. However, it is also a useful site for parents to visit.