Spelling City
Spelling City has math vocabulary lists

Glossary for upper grades in easily readable chart form

Parent Roadmaps to Common Core
Parent Roadmaps to Common Core – directly tied to Engage New York, has a brochure for each grade level that explains the concepts taught at that level. These might be worth printing to send home at the beginning of the year.

Illustrative Mathematics
A great resource site. It gives clearly explained examples of how to solve each type of problem for the Common Core Standards in a particular grade level. 

Inside Mathematics
This site has good materials for every standard. One outstanding feature is the Problem of the Month which gives a monthly problem related to the standards which cause students to apply the skills. The problems have levels to challenge students at their own level. Detailed explanations are provided.