This proceedings volume features selected papers presented at the 6th International Conference on Mathematics and its Applications in Science and Engineering – ICMASE 2025, held on July 15–17, 2025, in Plovdiv, Bulgaria. The works in this volume explore recent developments in the application of mathematics to science and engineering, with particular emphasis on mathematical and computational modeling of real-world problems. The contributions span several core and emerging areas of mathematics and its applications. Topics include number theory and integer sequences, algebraic structures, graph theory, and matrix theory; differential equations, operator theory, and geometric analysis; stochastic processes, queueing theory, and risk assessment; and computational and data-driven methods used in optimization, modeling, and machine learning. A substantial portion of the volume is devoted to mathematical modeling in ecology, biology, and network dynamics, alongside studies addressing educational innovation in engineering mathematics, mathematical diagnostics, and pedagogical approaches. Together, these works reflect the breadth of contemporary mathematical research and its interdisciplinary impact across scientific, engineering, and educational domains, making this volume of interest to researchers, practitioners, and graduate students. Organized annually since 2020 in different international locations, ICMASE brings together researchers, academics, and practitioners to exchange ideas, present innovative research, and foster interdisciplinary collaboration. ICMASE 2025 was organized as a hybrid conference, offering both in-person and online participation.
