Ask for Kids (formerly Ask Jeeves for Kids)
Andy Griffiths ("Just Stupid" etc)
Dav Pillkey (Captain Underpants)
http://www.no-dig-vegetablegarden.com/index.html
Maths Websites:
http://www.copacabana-p.schools.nsw.edu.au/Get_Smart_Pages/Get_Smart_Maths_s3_Space&Measure.html
http://www.aaamath.com/
http://www.factmonster.com/math/knowledgebox/
http://www.abc.net.au/countusin/games/game13.htm
http://www.topmarks.co.uk/Interactive.aspx?cat=14
http://www.coolmath4kids.com/fractions/index.html
