Resources should enable students to make sense of mathematical concepts. Introduced through play but then connected to patterns and predicability that can be also be expressed symbolically and graphically. This relates not only to primary grades but to middle School and high school where science and predicability, qualified through probes can be graphed and written symbolically.
You may find this article helpful for your literature review:
Mason, J., & Davis, B. (2013). The importance of teachers’ mathematical awareness for in-the-moment pedagogy. Canadian Journal of Science, Mathematics and Technology Education, 13(2), 182-197. doi:10.1080/14926156.2013.784830