Valuable as both a text and a reference, this concise monograph starts with a consideration of the calculus of finite differences and advances to discussions of the gamma and psi functions and other methods of summation. Subsequent chapters offer a summation of tables and an examination of infinite sums. The treatment concludes with a table of finite sums and helpful indexes. This volume was written by a prominent mathematician and educator whose interests encompassed the history of mathematics, statistics, modeling in economics, mathematical physics, and other disciplines. The book is suitable for students, researchers, and applied mathematicians in many areas of mathematics, computer science, and engineering.