Brunswick's Upper School mathematics program provides students with concepts and skills from a wide range of mathematical areas, including algebra, geometry, trigonometry, probability, and data processing. In all of these areas there is an emphasis on critical and logical thinking and the clear communication of mathematical ideas. Participating actively in all aspects of the learning process, the students progress to advanced topics, and are encouraged to develop the initiative required for the solution of complex mathematical problems. In order to encourage the number sense required in everyday life and to prepare students for the no-calculator sections of future examinations, a substantial amount of pencil-and-paper and mental arithmetic is involved in every course. In addition, technology is used to reinforce concepts and to tackle problems that cannot be solved by other means. To this end, every student is expected to have an approved graphing calculator.

The mathematics curriculum is flexible; a variety of courses is offered to accommodate the needs of all students, including those who are highly accelerated. Mathematics is required at Brunswick through the 11th grade, though nearly all students opt to continue with the subject up to graduation. The curriculum is divided into two tracks – honors and regular – and there is a small amount of movement between the tracks on the suggestion of the mathematics department. Generally speaking, students in both tracks study Geometry in the 9th grade, Algebra II in the 10th, Precalculus in the 11th, and Calculus in the 12th. In addition, an AP Statistics course is offered for those students who wish to supplement their mathematical studies. For students who finish AP Calculus BC prior to their senior year, Brunswick offers a selection of undergraduate mathematics courses administered by Stanford University 's Educational Program for Gifted Youth.
Faculty:
- Michael Allwood, Chair
- Anne Allwood
- Poonam Gupta
- Michael Harris
- Judene Pendergast
- Ron VanBelle
- Grace Warne
