Christopher Danielson (Ph.D, MSU) is a mathematics education professor at Normandale Community College in Bloomington, MN. He is the author of Common Core Math For Parents for Dummies, "Which One Doesn't Belong?" and was a curriculum writer for the Connected Math Project.
Talking Math With Your Kids
Which One Doesn't Belong?
Danielson's work influenced Mary Bourassa to create the "Which One Doesn't Belong" website. http://wodb.ca/
Common Core Advocacy
A bunch of MTMS pieces.