Game-Based Learning (GBL) founded on digital technology is a promising method for students to learn mathematical concepts and practice mathematical skills. To fully take advantage of technology and GBL, the GAMMA project aimed to make use of the time that the students already spend on their electronic devices and their knowledge and experience of digital games to enhance their mathematical knowledge and skills. The implementation of GBL founded on digital technology poses a challenge in education, with teachers playing a pivotal role as designers, facilitators, and guides in this approach. Therefore, they need to be supported in developing the knowledge and skills to take on these roles. In the GAMMA project, we have developed education materials for mathematics teachers who want to integrate GBL founded on digital technology effectively into their teaching practice. The materials could also be useful for teachers of other subjects who wish to integrate this method into their teaching.