For the past five summers, the authors have taught summer school to recent immigrants and refugees. Their experiences with these fourth-grade English language learners (ELL) have taught them the value of using models to build scientific and mathematical concepts. In this article, they describe the use of different forms of 2- and 3-D models to show students how, when, and why scientists and mathematicians use models. In addition, they capitalize on how models can enhance the use of discipline-specific language. The language of science goes beyond natural language (oral and written). To make meaning in science, they also make use of "mathematical relationships, visual representations, and manual-technical operations" (Lemke 2004, p. 38). Although teachers may use models as tools for learning, they may not as often see their use as tools for expressing understanding. The use of models for expressing meaning is particularly helpful when working with ELL students. (Contains 6 figures and 1 online resource.)