Christina Tondevold, Author of Fluency Through Flexibility, shared how to Help Kids Use Fingers Efficiently, the 4 Number Relationships that build Number Sense, and a Quick Way to Build Number Sense in less than 10 minutes a day.

She also shared lots of books and research of how kids learn number sense.  You can download those resources HERE.  The download is a copy of the slides that contained resources and the resources are linked, so just click them and it will take you to more information.