I found that reinforcing math concepts on the computer helps my daughter understand math concepts - especially if the games are useful. We've used online resources, but I just found this really useful site that a teacher put together to help his 1st grade special needs students practice math outside of the classroom. I think they are useful for any child who is learning a new math concept. I didn't find any of these links when I did a google search so I think having a teacher put together a list is even better than what I could do. They are really good sites all collected in a livebinde:
http://livebinders.com/play/play?id=2075