This project aims to improve our understanding of early math instruction and how to provide children with the best mathematical opportunities in these early and important years of school. We are collecting data on kindergarten, first-, and third-grade classroom instructional experiences in a large urban district through direct classroom observations. The goal is to compare instructional practices across grades and across schools within the same district serving students from very different economic backgrounds. We are also coding curricular materials to provide new and valuable information about the alignment of mathematics content across the early elementary grades (kindergarten through grade three). Through classroom observations, we will provide insight into the extent to which mathematics instruction in kindergarten varies across schools. By coding three different widely used early mathematics curricula, we will explore the extent to which instruction is likely to vary depending on the curriculum program that has been adopted.