Model-eliciting activities (MEAs) are not new to those in engineering or mathematics, but they were new to Melissa Parks. Model-eliciting activities are simulated real-world problems that integrate engineering, mathematical, and scientific thinking as students find solutions for specific scenarios. During this process, students generate solutions by hypothesizing, testing, refining, and extending their thinking while creating models (Lesh et al. 2000). Through the hands-on, performance-based tasks, students manipulate, discuss, and defend their ideas in small groups. As MEAs are integrated into the curriculum, the learning experiences may increase the depth of students' understanding and lead them to apply that knowledge to new situations (Garfield, delMas, and Zieffler 2012). MEAs integrate scientific, engineering, and the "Common Core State Standards" as students discuss and write their findings in a manner that clearly communicates the results of their work. In this article, Parks describes how she used model-eliciting activities to review content following the completion of a unit on ecosystems and climate (5-LS-2 Ecosystems: Interactions, Energy, and Dynamics; LS2.A Interdependent Relationships in Ecosystems). She created an MEA that would challenge students to build a cost-effective water filter to clean a (teacher-made) water sample of pollutants. Students' curiosity was piqued, and they actively engaged in the real-world problem solving that required multiple steps to take the project from brainstorm to building to testing and revising, all while discussing options with peers, which are practices outlined in the "Next Generation Science Standards" (Asking Questions and Defining Problems and Constructing Explanations and Defining Solutions). This collaborative process may be beneficial to English language learners as they integrate both social and academic language throughout the MEA.