It’s tough to know where to start when looking for Math resources online- there is so much good stuff out there. It’s even more difficult to know where to start when looking for math resources that are aligned to and address the common core standards. This list of math resources has been compiled by http://www.ccedtech.com to specifically help get a handle on Common Core. I’ve added a few more resources to their list. Here they are:
The National Library of Virtual Manipulatives: This site is developed by Utah State University to support K-12. It includes plenty of online exercises.
Inside Math (videos and lessons): A resource for math educators that you should be familiar with.
Interactivate– Common Core Aligned Lessons: A collection of digital interactive resources aligned to common core math. Similar to NSDL below.
Opus Math Problem Bank: This is a search engine to find math problems aligned to common core. It focuses on 7th and 8th grade.
Eureka Math– Common Core Math Maps: This is a pay site that has a free preview of their digital common core curriculum for grades K, 3, 6, and 9.
National Science Digital Library: Browse the Common Core Math Standards and find plenty of digital resources associated with key learning goals.
Math Video Sites:
I think you will find these sites a great help if you take a few minutes to look at them.