For K-12 science and math teachers, technology and engineering have always been relevant topics, albeit typically of a tacit or peripheral nature. Often teachers either purchased technology or constructed an apparatus from the technologies at hand and then employed it to demonstrate an application of a scientific principle, perhaps describing the behavior of the apparatus mathematically. For example, firing a projectile at a falling object in order to demonstrate that both are accelerating downward at the same rate (in the case of the projectile, neatly along the path of a parabolic arc). The focus was on the science and mathematics aspects of STEM, rather than on the properties of the technology or how to construct it.