In this second episode of the math fluency series, we explore the four essential number relationships that help students move beyond counting and develop true mathematical thinking. Learn about spatial relationships, one/two more or less, benchmarks of 5 and 10, and part-part-whole thinking—and discover how these relationships evolve from PreK through fifth grade. We'll look at why students get stuck using inefficient strategies and how building these foundational relationships transforms them into flexible problem-solvers who can see multiple pathways to solutions. Plus, get practical questions you can start asking tomorrow to assess and develop these critical relationships in your students. Free number sense assessment resources available at BuildMathMinds.com/208.