Lynn Steen  Lynn Arthur Steen (January 1, 1941 – June 21, 2015) was an American mathematician who was a Professor of Mathematics at St. Olaf College, Northfield, Minnesota in the U.S. He wrote numerous books and articles on the teaching of mathematics. He was a past president of the Mathematics Association of America (MAA) and served as chairman of the Conference Board of the Mathematical Sciences. Lynn Steen was born in Chicago, Illinois but was raised in Staten Island, New York. His mother was a singer at the N.Y. City Center Opera and his father conducted the Wagner College Choir. In 1961, Steen graduated from Luther College with a degree in Mathematics and a minor in Physics. In 1965 Steen graduated from MIT with a Ph.D in Mathematics. He then joined the faculty of St. Olaf College. At the beginning of Steen's career he mainly focused on teaching and helping develop research experiences for undergraduates. His teaching led Steen to begin to investigate the links between mathematics and other fields. He wrote many articles aimed for a non-mathematical audience about new developments in mathematics. The majority of his work in the 1970s was regarding mathematical exposition, communicating mathematical research to students, teachers, and the public. In the 1980s, Steen helped lead national efforts to modernize the teaching of Calculus and other areas in undergraduate mathematics. He helped broaden the mathematics major at St. Olaf by focusing the students work on inquiry and investigation. With the help of his mathematical colleagues, Steen made mathematics one of the five top majors for St. Olaf. St Olaf also became one of the nation's largest undergraduate producers in mathematical sciences. In 1992, Steen went on leave from St. Olaf, he served as executive director of the Mathematical Sciences Education Board at the National Academy of Sciences in Washington, DC. In 1995, he returned to St. Olaf and began working on special projects for the Provost office. In the late 1990s, Steen worked as a writer and editor in pioneering grade-by-grade standards that helped meet the mathematical requirements of college as well as careers. The campaign for similar standards that is seen nowadays is an evolution of his former efforts. In 2009 Steen retired from St. Olaf. He died June 21, 2015 of heart failure. He was survived by his wife of 52 years, Mary Steen.