This chapter highlights the elementary teachers’ viewpoint on difference in time allocated to teach students (4-year looping versus single-grade teaching), how these models relate to the teachers’ pedagogical knowledge, and how they influence teacher professional learning. As a result of having a looping system in Lithuania and a single-grade teaching programmatic approach in the USA, the teachers in Lithuania view their students from a developmental perspective and get to know them very well, which results in tailoring their instruction to their students. The American teachers learn about their students from test results and, thus, characterize them in terms of their membership in a higher- or lower-achieving group, which results in teaching their grade curriculum rather than specific students.