In Lower School science, students construct their knowledge by “doing” science. As student skills progress, their knowledge of science is refined and supported by their lab experiments. The Lower School science program uses a “spiral” approach in which concepts and skills taught in pre-kindergarten circle upward as they are refined, strengthened, and expanded upon in successive grades. Measurement is just one example of this. In the earthworm ecology project, kindergartners use string to measure the length of worms and produce a graph. The measurement skill develops and progresses through the years until fifth graders must employ highly precise measurement in millimeters to successfully complete a pendulum in the engineering and design unit.