**Alfred S. Posamentier** is an American educator and a lead commentator on American math and science education, regularly contributing to *The New York Times* and other news publications. He has created original math and science curricula, emphasized the need for increased math and science funding, promulgated criteria by which to select math and science educators, advocated the importance of involving parents in K-12 math and science education, and provided myriad curricular solutions for teaching critical thinking in math.

Dr. Posamentier was a member of the New York State Education Commissioner's Blue Ribbon Panel on the Math-A Regents Exams. He served on the Commissioner's Mathematics Standards Committee, which redefined the Standards for New York State. And he served on the New York City schools’ Chancellor's Math Advisory Panel.

Posamentier earned a Ph.D. in mathematics education from Fordham University (1973), a master's degree in mathematics education from the City College of the City University of New York (1966) and an A.B. degree in mathematics from Hunter College of the City University of New York.

**Ingmar Lehmann** is retired from the mathematics faculty at Humboldt University in Berlin. For many years, he led the Berlin Mathematics Student Society for gifted secondary school students, an organization with which he is still closely engaged today.

He is the author of numerous mathematics texts in Germany and the coauthor with Alfred S. Posamentier of some other books, including The Secrets of Triangles, The Glorious Golden Ratio, Magnificent Mistakes in Mathematics, and The Fabulous Fibonacci Numbers.