I know this is not geared towards toddlers or young children but I think khan academy
http://www.khanacademy.org/ is the best place for you to have a look around and familiarize yourself with higher levels of maths and then perhaps you could create activities yourself that will hold your child's level/interest particularly using PP presentations and collecting ideas from other websites and blogs. My 2 year old loves to watch a few clips off this great site. Just an idea!