eng Science and Education Publishing American Journal of Applied Mathematics and Statistics 2328-7292 2023-03-27 11 1 30 34 10.12691/ajams-11-1-5 AJAMS20231115 article Michael. Gr. Voskoglou mvoskoglou@gmail.com 1 Professor Emeritus of Mathematical Sciences, (Ex Graduate TEI of Western Greece), School of Engineering ¨C University of Peloponnese, Patras, Greece The present work focuses on a classroom application for evaluating the effectiveness of the Flipped Learning methodology for teaching mathematics to management students. Using linguistic (qualitative) grades, the assessment of the mean student performance is realized with the help of grey numbers and the assessment of their quality performance by calculating the Grade Point Average (GPA) index. A neutrosophic assessment method is also applied for evaluating the overall student performance, because the instructor had doubts about the accuracy of the grades assigned to some students. http://pubs.sciepub.com/ajams/11/1/5/ajams-11-1-5.pdf flipped learning fuzzy assessment methods grey numbers (GNs) GPA index neutrosophic sets (NSs) neutrosophic triplets