In the 2018 General Education Curriculum in Mathematics, the mathematical thinking and reasoning competency is the first core component of mathematical competencies that needs to be formed and developed for students. This competency represents the most essential characteristic of learning mathematics. The mathematical thinking and reasoning competency not only plays an important role in teaching and forming new knowledge but also helps students solve practical problems. In this article, we learn about the manifestations of the mathematical thinking and reasoning competency, and propose directions to foster this competency for 11th-Grade students through teaching practical applications of exponential functions with the aid of information technology.