We present a new highly interactive computer animation tool to increase the mathematical skills of deaf children. We aim at increasing the effectiveness of (hearing) parents in teaching arithmetic to their deaf children, and the opportunity of deaf children to learn arithmetic via interactive media. Using state-of-the-art computer animation technology we have designed and modeled three 3-dimensional virtual signers. The signs for mathematical terminology, performed by a non-hearing signer, have been captured with an electro-mechanical motion capture system and have been applied to the 3D characters. Macromedia Director MX Shockwave Studio has provided the platform for the design of interactive learning activities and for Web delivery. Smoothness of motion (in real time) and interactivity have been achieved via a new method of programmable blending of animation segments. Our program is the first attempt at using interactive 3D animation to improve the mathematical abilities of deaf pupils. Though our research follows the general trend of systems of 3D animated sign language (none of which has been geared specifically toward mathematics), we have made progress of a nature qualitatively different from previous work. Focusing on the need to represent the signs with clarity, realism, and emotional appeal for deaf children, we have invested our research efforts in developing a very natural, nonmechanical animated representation of the signs. The realization of this natural gesture language by interactive computer animation has been the main challenge that this research has met and solved.