Attention to early childhood mathematics instructional strategies has sharpened due to the relatively poor mathematics performance of U.S. students in comparison to students from other countries and research evidence that early mathematics skills impact later achievement. Early Childhood counting skills form the foundation for subsequent mathematics learning. In this article, we discuss the milestones of counting development and examine preschool classroom mathematics observations through the lenses of two CLASS Dimensions, Concept Development and Instructional Learning Formats. Recommendations for effective instructional strategies around counting and suggestions for incorporating mathematics instruction into storybook reading are provided. (author abstract)