The areas of Science, Technology, Engineering and Mathematics, called STEM careers, are important fields of knowledge for society nowadays. Among the basics subjects of these careers is Mathematics, but many young students present difficulty to understand very basic mathematical concepts and logical thinking activities. This learning process is very complex and demands a lot of motivation by part of the students. In this sense, educational games can act as an interesting and stimulating helping tool for them. In Brazil, the levels of proficiency on rational numbers in their fractional representation presented by students aged between 9 and 12 years, in general, are low, mainly because in local culture the fractional representation is not common at the daily activities. The educational games to teach this topic in Portuguese are few, so it has motivated us to develop a game to teach fractions entirely in Portuguese language, but able to be adapted to other languages of the region, like Spanish. In this paper, we present such a game, called FracPotion, developed as an Open Educational Resource to teach about fractions to children. The game was experienced by a group of students in an elementary school at São Paulo city, Brazil, and the preliminary results were positive.