The purpose of this study was to investigate the potential of a tangible game, Inclusive Glossary of Mathematical Terms (GIM), to support the teaching of math and Portuguese sign language (Língua Gestual Portuguesa; LGP) to preschool and first-grade children, with an emphasis on inclusive education, knowledge acquisition, and engagement. GIM is composed of physical cards that are complemented by digital videos that run on an interface designed for this game. The game consists of two sets of cards and respective animations. As an inclusive math glossary, it also includes videos where concepts, characters, and objects are identified through images, words, and sign language. During the development process of GIM, it was possible to involve a multidisciplinary team, of which a Deaf sign language teacher and a sign language interpreter were part to ensure the clarity of the sign language and refine the written sentences accompanying the glossary. In order to validate its contents, a focus group of preschool and primary teachers specialized in the teaching of Deaf and Hard of Hearing (DHH) children was formed. A total of 120 children, aged between three and eight years old (M = 5.61; SD = 0.78), and seven LGP and special education teachers from three Portuguese schools participated in the study. The children used GIM in their classrooms, with the assistance of the participating teachers, who were subsequently interviewed to assess their engagement, interest, and learning outcomes. The interviews were analyzed using content analysis procedures, including descriptive statistics and Pearson correlations. The results indicated that GIM has the potential to effectively support the teaching of mathematics and LGP to preschool and first-grade children, especially in inclusive education contexts. The tangible nature of the game facilitated children's understanding of mathematical concepts and LGP, leading to improved involvement in the teaching-learning process. Moreover, the game promoted awareness of diversity and the principles of inclusive education, making it a valuable tool for promoting social inclusion and understanding. However, the study has reduced sample and context-specific limitations, suggesting a need for further research in this area.