This study evaluated the impact teaching of exponential functions through a problem-solving approach to students in secondary education. Based on the theory proposed by Onuchic (1999), we created four activities involving problems to introduce the concepts related to exponential functions to tenthgrade students and to verify the acquired knowledge of eleventh-grade and twelfth-grade students. The problems involve the population growth of bacteria and the half-life of a drug. All the students welcomed the new didactic proposal. The tenth-grade students were able to understand the new concepts based on problem-solving teaching and eleventh-grade and twelfth-grade students presented difficulties regarding the topic of functions.