The Scratch programming tool is an effective tool for the logical problem-solving skills of middle school students with its ease, richness of their visual characters and all their objects, as well as processing skills. In particular, the fact that research has shown that teaching with Scratch has a positive effect on students' mathematical achievements in algebraic expressions indicates that a different teaching method can be used in the field of algebra learning. Therefore, it is believed that the use of mathematics teachers in the lesson by learning this program before service will contribute to the students ' learning and love of mathematics. The aim of the research is to examine the opinions of mathematics teachers about the games that prospective teachers design in the Scratch program. The participants of this study, in which the case study was conducted, are six mathematics teachers. The research process was carried out in three stages. In the first stage, 13 games were designed by prospective teachers about achievements in algebraic expressions. In the second phase, six mathematics teachers were asked to score these games according to the revised rubric of Li et al (2013). In the third stage, teachers' opinions on the reasons for the scores they gave to the games were taken. Kappa coefficients were calculated for the scoring compliance among teachers. Qualitative data analysis techniques were used in the analysis of teacher opinions. In this study, it was revealed that most teachers found the games interesting, cle, and instructive/reinforcing. Some teachers found the games original, while others stated that they were classic games that they often encountered. In addition, some teachers emphasized that they can use these games in their lessons, while others stated that they cannot use them in their lessons for reasons such as missing instructions, code errors, and lack of program.