Welcome to the OER companion for Baylor University’s Math 1121: The Calculus Supplement Course! Math 1121 is an optional, co-requisite course for students enrolled in Calculus 1. This OER was designed to provide ‘just in time’ support for the algebraic, trigonometric, and geometric relationships undergirding Calculus 1. The topics and content were deliberately sequenced to coincide with the topics and content Calculus 1 students engage as they study limits, derivatives, applications of derivatives, and integration. Therefore, this text first reviews the essential functions from Pre-Calculus that students need to be successful in Calculus 1. Then, it examines the properties and algebraic transformations of those functions and reinforces strategies for analyzing functions. Finally, it bolsters the relationships between algebra and geometry that the Fundamental Theorem of Calculus and integrals bring together for Calculus 1 students. Although this OER was designed to support Calculus 1 students, there is almost no Calculus within these ‘pages.’ Rather, the focus is on everything that happens in a Calculus problem after that first Calculus step. Enjoy!