"The Heart of Mathematics: An Invitation to Effective Thinking" is a comprehensive textbook written by authors Michael Starbird and Edward B. Burger. Published by Key Curriculum Press in 1999, this hardcover book delves into the subject area of mathematics, focusing on history, philosophy, and general mathematical concepts. With 646 pages, this textbook provides a detailed exploration of mathematical principles and encourages readers to engage in effective thinking. Ideal for students and educators alike, this textbook is a valuable resource for those looking to deepen their understanding of mathematics through a philosophical lens.