It is widely acknowledged that the traditional calculus sequence required of most molecular science majors, consisting of a year of differential and integral calculus and possibly a semester of multivariate calculus, does not provide the mathematical background needed for success in the quantum mechanics and statistical thermodynamics courses that follow. Mathematical Methods for Molecular Science, by Chemistry Professor John Straub, is designed to support a one-semester course that builds on the introductory calculus sequence and covers critical topics in multivariate calculus, ordinary and partial differential equations, and linear algebra. Published through a Creative Commons license, the full textbook is available for download.