Visitors to the fourth- and fifth-grade classrooms are likely to find tables and walls decorated to reflect a culture or topic currently being studied. Artifacts from foreign countries, plant experiments, or an exhibition of self-portraits are displayed throughout the 4/5 space on the top floor of the Lower School building. The fourth- and fifth-grade students are clearly active learners who are excited to explore their subjects in depth.

Reading, writing, math, and science skills are honed during this two-year period. The students' writing now takes on greater detail, and editing and revision are part of the process. Through research on the fourth- and fifth-grade Independent Projects, students are prepared for the term paper work they will begin in sixth grade in the Middle School. In math, the 4/5 curriculum moves students through fractions and decimals as well as making and interpreting graphs. Math facts are reviewed and honed.

Citizenship is a unit of study in the 4/5 classroom, as students look at immigration and U.S. and world geography. In Science, aerodynamics, weight, mass, volume and density, volcanoes, plate tectonics, and glaciers are explored, with great enthusiasm and experimentation.