We describe a tool which was developed as a Masters project to help students learn the concepts of reasoning with uncertainty. While the initial implementation has focused on Dempster-Shafer theory, the tool is designed so that it can be expanded to other models of uncertain reasoning. The tool uses interactive graphical representations, together with animation and color, to convey the principles of reasoning with uncertainty. It runs on the Unix platform under the X-window system and uses the SUIT toolkit (Conway & Pausch & Passarella 1992). A demonstration of the tool will be included with the presentation of this paper.