Calculus Gems, a collection of essays written about mathematicians and mathematics, is a spin-off of two appendices (""Biographical Notes"" and ""Variety of Additional Topics"") found in Simmons' 1985 calculus book. With many additions and some minor adjustments, the material will now be available in a separate softcover volume. The text is suitable as a supplement for a calculus course and/or a history of mathematics course, The overall aim is bound up in the question, ""What is mathematics for?"" and in Simmons' answer, ""To delight the mind and help us understand the world"". The essays are independent of one another, allowing the instructor to pick and choose among them. Part A, ""Brief Lives"", is a biographical history of mathematics from earliest times (Thales, 625-547 BC) through the late 19th century (Weierstrass, 1815-1897) that serves to connect mathematics to the broader intellectual and social history of Western civilization. Part B, ""Memorable Mathematics"", is a collection of interesting topics from number theory, geometry, and science arranged in an order roughly corresponding to the order of most calculus courses. Some of these sections have a few problems for the student to solve. Students can gain perspective on the mathematical experience and learn some mathematics not contained in the usual courses, and instructors can assign student papers and projects based on the essays. The book teaches by example that mathematics is more than computation. Original illustrations of influential mathematicians in history and their inventions accompany the brief biographies and mathematical discussions.