We provide in-depth information and analysis on three activities for use in History of Mathematics courses taught either in a traditional semester format for undergraduates or in a summer professional development course for middle school teachers. These activities require students to be active participants in their own learning. They also complement the more traditional mathematics content of such courses. The first focuses on accuracy of historical information; the second on biographical aspects of major contributors to mathematics; and the third on the accuracy of historical infomation, problem posing and questioning, and effective research. For each activity, we discuss the goals, implementation, outcomes, observations, and possible modifications.