Abstract: We present VectorPad, a novel, pen-based application for three-dimensional vector mathematics visualization. VectorPad allows users to define vectors and perform mathematical operations on them through the recognition of handwritten mathematics. The user interface consists of a sketching area, where the user can write vector definitions and operations such as addition, subtraction, scalar multiplication, and cross product, and a 3D graph for visualization. Vectors are visualized dynamically on the graph, which can be manipulated by the user. We also performed a short, informal user study evaluating the user interface and visualizations of VectorPad. Results from the study show that visualizations were generally well liked but the application needs to provide a more comprehensive set of visualization tools as well as refinement to some of the animations.