Water is one of the most important resources on Earth: there is no life, environment and economic production without it. No human activity takes place without water. As traditional school curricula do not always properly prepare individuals for the complex global reality, including limited water resources, critical environmental education becomes a necessity, a continuous and permanent process that must cover all school levels and stages of formal and informal education. Due to its importance, environmental education is transversely included in the documents that guide the curricular structure of Elementary School in Brazil. In this context, the purpose of this research work was to create a board game, aiming to contribute to the environmental training of students. The game, called “Dropwise”, was designed to be applied in the sixth grade Mathematics classes of Elementary School. The game aims to enable the learning of practices to reduce water consumption, including recognizing places at home that can be equipped with water-saving devices, for example, dual-flush toilets and aerators on kitchen and bathroom faucets. The proposal meets the competencies of the National Common Core Curriculum for the sixth grade, working on problem-solving that uses research data on environmental contexts, enabling critical thinking. During the research, working with undergraduate students in Mathematics, who are, actually, prospective teachers, was proposed. The involvement of teachers in training is important for the inclusion of sustainability in the curricula of undergraduate programs. Preliminary results highlight the potential of the game in learning Mathematics contents and in the reflection on water conservation. The integration of games into education is important, as it represents a playful approach to learning. By playing, children develop an understanding of the social world around them.