​About the Authors Lawrence S. Leff is Former Assistant Principal, Mathematics Supervision, at Franklin D. Roosevelt High School in Brooklyn, New York. Christina Pawlowski (revising author) is a math teacher at Commack High School in Commack, New York. She is an NYSMTP Emeritus and was the Association of Mathematics Teachers of New York State (AMTNYS) County Chairperson 2018. She was also a NYS Teach of the Year Finalist and received the Governor's Teaching Award. About the Publisher In the 1930s, Manuel H. Barron opened a bookstore in Brooklyn, New York. People from the community asked Mr. Barron about books that might be available to help their children study for the New York State Regents exams. After realizing there wasn't anything available, Mr. Barron's created his own study guides. 80 years later, Barron's has helped millions of people prepare for their next step.