Paul Zorn was born in India, and had his primary and secondary schooling there. He did his undergraduate degree, in mathematics and English, at Washington University in St. Louis, and his Ph.D., in complex analysis, at the University of Washington, Seattle. Since 1981 he has been on the mathematics faculty at St. Olaf College, in Northfield, Minnesota.

In 1987 Paul Zorn received the Allendoerfer Award for mathematical exposition from the Mathematical Association of America (MAA). He was chief editor, from 1995 to 2000, of the MAA journal Mathematics Magazine. He has also served on the Council of the American Mathematical Society and on the Board of Governors of the MAA. In 2011 and 2012 he served as President of the MAA.

The first edition of Understanding Real Analysis was published by AK Peters in 2010. The present (second) edition was published by CRC Press in 2017. Paul Zorn has also published (with his late co-author, Arnold Ostebee) a series of calculus textbooks that draw on computing to promote graphical, numerical, and symbolic viewpoints.

Preliminaries: Numbers, Sets, Proofs, and Bounds. Sequences and Series. Limits and Continuity. Derivatives. Integrals.