Meet the Leaders

Nils Ahbel, Deerfield Academy, Deerfield, MA
Nils is an author of 3 UCSMP textbooks and for the past 15 years has made his own Alternative to Precalculus (FST) course available for free online at He has done product development for various companies since 1992, including TI and the iPad app FluidMath. Nils regularly speaks at conferences including NCTM, NCSSM, UCSMP, 25 years at The ASG Exeter Conference (twice an evening speaker), TSM in England, and the TTL Institute in Australia. He also speaks at schools about relevant mathematics curriculum and innovative uses of technology.
David Bannard, Collegiate School, Richmond, VA
David has been teaching since 1969 including 17 years at the Groton School and the past 27 years at the Collegiate School in Richmond, Virginia. As one of the original beta testers for The Geometer's Sketchpad, he has been using technology in the classroom since the first conference in 1985. He now makes extensive use of Geogebra. He has participated in almost every Anja S. Greer Conference since 1985.
Kevin Bartkovich, Phillips Exeter Academy, Exeter, NH
Kevin was a teacher for 17 years at the N.C. School of Science & Math, where he was part of a department that developed curricular materials for contemporary high school math and wrote textbooks for precalculus and calculus. He then embarked upon a 10-year adventure in Uganda where he and his wife JD established Christ School - Bundibugyo, a boarding secondary school located in a remote village near the border with Congo. Kevin and JD returned with their 4 children (now 5) to the US in 2008 and moved to Exeter in the fall of 2009, where Kevin began teaching in the math department at PEA.
Eric Bergofsky, Phillips Exeter Academy, Exeter, NH
Eric has taught high school mathematics since 1973 and is currently the Department Chair and in his 39th year as an instructor at Phillips Exeter Academy. He is a former leader and director of the Exeter Math, Science, and Technology Conference, and was also the director of the Exeter Mathematics Institute from 1992-2013. Eric has had a long time interest in the use of technology activities as well as hands-on activities in the classroom. Eric co-authored the book "Exploring Algebra with The Geometer's Sketchpad", published by Key Curriculum Press.
Mary Bourassa, West Carleton Secondary School, Ottawa, Ontario, Canada
Mary currently teaches mathematics at West Carleton Secondary School in rural Ottawa, Canada. She is a strong advocate of the appropriate use of technology in the classroom. She connects with other educators via Twitter (@MaryBourassa) and learns everyday from others' blogs. She has presented workshops across Canada, the US and Australia. She is a past director and Vice-President of the Ontario Association for Mathematics Education. Winner of several awards from NCTM and OAME, Mary continually strives to learn new and better ways of helping students learn and love mathematics.
Floyd Bullard, The North Carolina School of Science and Mathematics, Durham, NC
Floyd has taught high-school mathematics for seventeen years, including two as a Peace Corps Volunteer in Benin, West Africa, and is currently at the North Carolina School of Science and Mathematics. Floyd has been involved with the AP Statistics program since 2002 and has recently served on the test development committee. In May 2009 he received a PhD in statistics from Duke University; his dissertation was about exoplanet detection. Floyd lives in North Carolina with his partner Rick.
Dan Butler, Mounds View High School, Arden Hills, MN
Dan has been teaching mathematics at the middle school and high school level for the past 32 years in the public school system. He has taught all mathematics courses from prealgebra to multivariable calculus and linear algebra. Dan gives numerous workshops in mathematics both in the United States and abroad. He has been involved in professional development workshops for the past 25 years, including ten years as a teacher leader in the Woodrow Wilson Fellowship Foundation and 26 years as an instructor in the Anja S. Greer Conference. Dan likes to live by the motto, "See the World, Do Math."
Jonathan Choate, Groton School, Groton, MA
Jonathan has taught mathematics at Groton School since 1966. He is the co-author of The Dynamics Toolkit, four books covering topics in fractal geometry and chaos theory. He has served on both NCTM's Algebra and Discrete Mathematics Task Forces. His column, Geometer's Corner, is a regular feature in COMAP's Consortium newsletter, and he has created a web site dedicated to the teaching of three-dimensional geometry which can be found at The website includes information about how Google SketchUp can be used in the teaching of geometry.
Ken Collins, Charlotte Latin School, Charlotte, NC
Ken has a B.S. in physics and M.S. in math from BPI/NYU and a Ph.D. from Purdue University. He has taught for fifty one years in middle school through graduate school. His focus is on effective use of technology and applying mathematics to analyze current issues. He teaches calculus and algebra II with extensive use of calculator technology. Ken gives five to ten workshops each year at regional and national conferences of NCTM, ACA, and T^3. He is currently writing curriculum material for classroom explorations in mathematics and using mathematics to analyze critical problems in our society.
Al Coons, Buckingham Browne & Nichols School, Cambridge, MA
Al has taught mathematics for 38 years at Mercersburg, Andover, and Buckingham Browne & Nichols. He was an early advocate for student-centered, connected education. He is a past editor of Tech Tips in The Mathematics Teacher. He organized and presented at some of the earliest meetings of AP Statistics teachers, and was an AP grader and table leader. Other workshops include Taxicab Geometry, Teaching Chaos in Geometry & Precalculus, and a Roller Coaster Project in Calculus. Al coached seven sports, was an outdoor leader, and can be found enjoying the mountains and seas during vacations.
Natasha Crawford, National Cathedral School, Washington, DC
Natasha has taught mathematics for 13 years, including three at Phillips Exeter Academy. She currently teaches at The National Cathedral School in Washington, D.C. She has taught at both the high school and community college level. Natasha holds a BS and MST from Clark Atlanta University and an MS from San Diego State University. She is particularly interested in using a problem based approach to her classes. She has led workshops on using Exeter's problem sets in traditional class settings and Intro to Desmos for Algebra.
Diana Davis, Northwestern University, Evanston, IL
Diana works at Northwestern University, teaching college students and doing research in geometry. Diana attended Phillips Exeter Academy as a highly engaged high school student, and also taught in the PEA math department for a year as an intern, and at PEA summer school for five years. This will be her fourth time as a leader at the conference. She loves to explain things, especially by drawing pictures and making geometric models. In the wider world, she is best known for making a video that explains her math research through dance, which "went viral." Check it out:
Anthony DiLaura, Zeeland Public Schools, Zeeland, MI
Anthony is a high school math teacher, STEM educator, and instructional technology specialist. In 2013 he was awarded the “Apple Distinguished Educator” title and in 2015 he was nationally recognized as the “iBooks Author Trainer of the Year” for his innovative workshops that help educators author multi-touch textbooks for the iPad. Anthony teaches in a 1:1 iPad environment and testifies to the profound impact iPads and iBooks have on student learning. Anthony enjoys sharing his knowledge and enthusiasm while helping teachers redesign their instruction by adding iPads to the math equation!
Peter Flynn, Texas Instruments/The University of Melbourne, Melbourne, VIC, Australia
Peter was a secondary school mathematics teacher for approximately a decade before joining the University of Melbourne's Graduate School of Education where he currently teaches a variety of mathematics and mathematics education subjects. His mathematics education interests involve implementing technology into mathematics teaching, learning and assessment. Peter is an experienced T-cubed Instructor who has presented many workshops to both Australian and international audiences.
Karen Geary, Phillips Exeter Academy, Exeter, NH
Karen has taught at Phillips Exeter Academy since 1996, in the Science and Mathematics Departments. She has taught summer math courses through the PEA Summer School Outreach, for neighboring school districts. Through the Exeter Math Institute and the Exeter Humanities Institutes, she has conducted workshops on student-centered learning. Since 2006, Karen has worked closely with the Exeter math curriculum, participating in summer editing work and writing and developing teacher commentary for the entry-level (Math 1) materials. Currently, she is also serving as the Dean of Academic Affairs.
Julie Graves, North Carolina School of Science and Mathematics, Durham, NC
Julie has taught mathematics at the North Carolina School of Science and Mathematics since 1985. She has developed curriculum for high school teachers and students in precalculus and calculus courses and was involved with distance learning broadcasts for many years. She has been an instructor in numerous workshops for teachers focusing on Precalculus, Calculus and Statistics. She is interested in using Geogebra in the Calculus classroom as a learning tool, and hopes to learn about complex systems. When school is not in session she is knitting or quilting or in her garden.
Frank Griffin, Cate School, Carpinteria, CA
Frank has taught at Cate School (CA) since 1979, serving as Department Head from 1988 to 2015 and Director of Studies from 1995 through 2003. He is the holder of a teaching chair at Cate and recipient of the Tandy Technology Scholar award. Frank has taught courses in economics and geography and has coached basketball and tennis. Frank was a recipient of a Woodrow Wilson Foundation summer Fellowship in mathematics in the summer of 1985, and this experience led to numerous workshop opportunities in mathematics and technology. He has been a leader at the Anja S. Greer Conference since 1995.
Aviva Halani, Phillips Exeter Academy, Exeter, NH
Aviva has B.A. from Wellesley, and an M.A. and a Ph.D. from Arizona State. Though her degrees are in mathematics, her research has focused on students' problem solving approaches to counting problems, instructional interventions, and student understanding of calculus concepts. She has presented her results at numerous conferences. In Arizona, she was a Math Content Expert for Adaptive Curriculum, an ed tech company which develops highly interactive digital math and science lessons, and taught at ASU. She has been teaching various courses from algebra to calculus to proof at Exeter since 2013.
Maria Hernandez, The North Carolina School of Science and Mathematics, Durham, NC
With over 25 year of teaching experience, Maria has developed curricula for high school students in various mathematics courses. She has lead teacher collaborations via distance learning and has taught workshops for courses from Algebra I to AP Calculus. Her focus is using mathematical modeling, discovery-based activities, technology and real-world problems to engage students as active learners in the mathematics classroom. Maria received The 2009 Presidential Award for Excellence in Mathematics Teaching and The UNC Board of Governors Award for Excellence in Teaching in 2013.
Jeff Ibbotson, Phillips Exeter Academy, Exeter, NH
Jeff has been teaching in secondary schools since 1995 after teaching at Merrimack College and the State University of Buffalo for 8 years. He is a student of Zbigniew Zielezny and earned his Ph.D. in Distribution Theory in 1989. He created a "math for teachers" seminar course while at Merrimack that was based on the use of historical materials and is a vigorous proponent of teaching the history of mathematics. He has been teaching a course in history of math at the secondary level at Exeter since 2002. He holds the Smith Teaching Chair in Mathematics.
Doug Kuhlmann, Phillips Academy, Andover, MA
Doug recently retired after 40 years in secondary boarding schools, the last 31 at Philips Academy. He received his B.S. in math from St. Louis U. in 1968, and his Ph.D. from Northwestern in 1978. He enjoys learning and teaching mathematics and is particularly interested in using GeoGebra in precalculus and calculus courses in high school. An active participant on the AP Calculus EDG, he has studied at Cambridge University during his first sabbatical and at Boston University during his second. He enjoys walking with his wife along Plum Island beach and also enjoys singing in the choir.
Ron Lancaster, University of Toronto, Toronto, Ontario, Canada
Ron is an Associate Professor at the University of Toronto where he teaches mathematics methods courses for future middle and high school teachers. He has over 20 years of experience teaching grades 7-12 mathematics. Ron's professional activities include consultations and conference presentations in North America, Asia, England, Abu Dhabi, Dubai, Qatar, and Africa. Ron is an author for NCTM's (The Mathematical Lens) Math Teacher and member of the Advisory Board for the Museum of Mathematics in New York City. He is the recipient of the 2015 Fields Institute Margaret Sinclair Memorial Award.
Mike May, Saint Louis University, St. Louis, MO
Mike earned his Ph.D. in mathematics from U.C. Berkeley. He has worked on appropriate ways to incorporate technology into teaching for more than 20 years. He has made presentations and published on a variety of technologies including: designing computer classrooms, appropriately using graphing calculators, Maple, Excel, applets, GeoGebra, and automated homework systems. Mike is an AP reader, a PREP workshop leader (, a Fullbright specialist in math ed, an MAA trainer for WeBWorK, and has designed material used in MyMathLab.
R. J. McDaniel, Boys' Latin of Philadelphia, Philadelphia, PA
R. J. received a BS in Civil Engineering from the University of Kansas, but swiftly moved to Yosemite National Park and never became an engineer. His initial foray into education was as a mathematics teacher and director of student activities at a boarding school in Ontario. His love of games and competition continually impacts his approach to teaching mathematics. R.J.has lived in Washington, Kansas, Louisiana, California, Canada, Germany, and for the past Ten years has resided in Philadelphia where he is the Math Department Chair and Head Basketball Coach at Boys' Latin of Philadelphia.
Stuart Moskowitz, Humboldt State University, Arcata, CA
Stuart plays with puzzles when not teaching math. More important, he uses puzzles to teach math. Besides puzzles, Stuart has a passion for history, technology, and multiculturalism as ways to make math come alive. Through Stuart’s 20+ years teaching, he has led workshops, been a math coach, chaired conferences, and authored books and resource materials. Currently, Stuart blends puzzles and history by exploring the mathematical puzzles and paradoxes of Lewis Carroll. His current passion is showing teachers and students that mathematics comes from all over the world, not just western Europe.
Ira Nirenberg, Benjamin Franklin High School, New Orleans, LA (retired)
Ira worked as a geophysicist for six years prior to entering the teaching field. His teaching career spans 30 years having taught at Benjamin Franklin High School and Lusher High School in New Orleans, LA, the University of Chicago Laboratory Schools and several universities. He has taught AP Physics C & B, Astronomy and much of secondary mathematics. He has also taught in Hong Kong and Australia. He has written 4 books; Intermediate Physics, Living With Math, the Fraction ThinkBook-Bridging the Fraction-Algebra Gap and, Alabama Whistle (fiction). This will be his 17th year at the Conference.
Philip Rash, North Carolina School of Science and Mathematics, Durham, NC
Philip is in his twelfth year as a member of the NCSSM Mathematics faculty. A NC native, he earned Bachelor and Masters degrees in western NC, and has high school and university teaching experience prior to NCSSM. At NCSSM Philip teaches Precalculus, Calculus, Statistics, and some post-calculus elective courses. He's also very involved with math contests, including co-chairing the NC State Math Contest committee of the NC Council of Teachers of Mathematics. Philip is also a 2008 recipient of the MAA Edyth May Sliffe Award, as well as other teaching awards at his school.
Carmel Schettino, Deerfield Academy, Deerfield, MA
With Problem-Based Learning as her specialization, Carmel obtained a Ph.D. in Math Education while teaching at the secondary level for many years. She is passionate about helping teachers grapple with the pedagogical and curricular questions that rise when PBL is brought into the math classroom. Other areas of expertise include gender equity, discourse, technological implications and PBL's relationship to the Common Core. Carmel has consulted for a number of schools, presented for the NCTM and published articles with respect to PBL in the Secondary Mathematics Classroom.
Philip Todd, Saltire Software, Tigard, OR
Philip is the President and CTO of Saltire Software. Founded in 1989, the company develops mathematical software, most recently the products Math Illustrations and Geometry Expressions. Philip has been PI on several NSF grants and mentored high school student interns over the last 10 summers. He has presented at teachers' conferences both in the U.S. and internationally. He is the author of 3 mathematical iBooks. Philip has Masters Degrees in Mathematics from Cambridge University and Georgia Tech, and a PhD in Mathematical Biology from Dundee University in Scotland.
Ray Williams, St Mark's Anglican Community School, Perth, WA, Australia
Ray has been a teacher of mathematics and science for the past 40 years and is currently the Head of Mathematics at St Mark's Anglican Community School in Perth, Western Australia. St Mark's mathematics classrooms all have TI-Nspire Navigator Wireless Networks and wireless data projection of PC Tablets. As well as presenting at international and national conferences, Ray has presented workshops to teachers and parents in Learning Technologies and is a regular presenter at the T Cubed International, MAV and the Mathematics Association of WA on teaching mathematics with technology.
Ian Winokur, Greenfield Community College, Greenfield, MA
Ian has been teaching mathematics since 2001 at the high school and college level. He has been at Greenfield Community College since 2009. He is interested in the use of technology to improve student learning. Ian first solved a Rubik's Cube in 2003 and has been hooked ever since. He has competed in about 25 official tournaments with a fastest competition average of 15.20 seconds.
Gary Young, St Mark's Anglican Community School, Perth, WA, Australia
Gary has been a teacher of mathematics in Western Australia and in England for over 30 years. He is currently Assistant Principal:Academic at St Mark's Anglican Community School. Gary has a long history of using technology to enhance the learning of mathematics. The approach that Gary takes looks at collecting real life data and how that data can be used to explore mathematical relationships. The aim is to show how mathematics is there in every day life.