With increasing technological changes and needs in society, technology and engineering education has received much attention in school science. Yet, technology traditionally has been subordinated to science or simply taken as the application of science. This position has resulted in a limited understanding of teaching technological and engineering education. This study questions the traditional view of technology in school science by examining children's action and learning in the course of designing and building cantilever bridges in science classrooms. We adapt Heidegger's articulation of the four causes known to philosophy in the Greco-Roman tradition--causa materialis (material), causa formalis (form), causa finalis (purpose), and causa efficiens (effect-producing)--to analyze elementary children's technology design activities. The study suggests that children's technology has certain dimensions of knowing-how, i.e., there is an instrumentality that goes beyond scientific knowledge. We suggest that the practice of technology and engineering education, which mainly focuses on children's scientific knowledge, needs to be reexamined and reframed to develop holistic ways of teaching technology.