Materials cover basic math concepts and beginning addition.  For kindergarten and 1st grade.

Books
12 Ways to get to 11 by Eve Merriam
Adding It Up by Rosemary Wells
Addition Subtraction: 1
Math: Grade 1 
Math Basics: 1
Math Readiness: K-1      
Math to Learn Handbook (For Grades 1-2)
Mission: Addition by Loreen Leedy
Monster Math Picnic by Grace MacCarone
Transition Math: K-1

Realia
Addition 0-12 Flash Cards