In this paper we discuss manipulatives and hands-on investigations for Calculus involving volume, arc length, and surface area to motivate and develop formulae which can then be verified using techniques of integration. Pre-service teachers in calculus courses using these activities experience a classroom in which active learning is encouraged and investigations which can be used with their future middle school classes. Their study of calculus gives them a broader understanding of the formulae developed in the investigations. (Contains 6 figures.)