Final answer:
The novel does not specifically state how many years Mr. Terupt has been teaching, but he appears to be relatively new to the profession.
Step-by-step explanation:
In the novel Because of Mr. Terupt, it is not explicitly stated how many years Mr. Terupt had been teaching. However, there are hints throughout the book that suggest Mr. Terupt is relatively new to the profession, implying that he has not been teaching for many years. Since the information provided from the excerpt does not directly relate to Mr. Terupt's teaching experience, we cannot determine the exact number of years he has taught based on that dialogue alone.