Engaging Minds, One Equation at a Time: Meet Mr. Messler

Originally posted Nov. 18, 2024; updated Dec. 15, 2025

Morrow House math teacher David Messler makes learning about fractions, ratios, linear equations, polynomials, and number theory fun.

“Students come to my class every day fully engaged and ready to learn. My goal is to teach students and help them understand and love math like I do,” he says.

“Mr. Messler explains concepts clearly and concisely, and I always appreciated the faster pace of his teaching,” says Yael P. ’25, a freshman at Horace Mann. “He also goes above and beyond any given curriculum, like when he showed us a proof of the quadratic formula just for fun!”

Messler was drawn to math from an early age because of its precision. He loves that math isn’t ambiguous — it’s filled with equations and patterns that always lead to an answer.

He decided to become a math teacher because of his affinity for the subject, and students have long appreciated his charismatic way of teaching it. He’s even been known to draw a crowd!

Messler recalls an instance from his college days when he was in the library tutoring some students on using the definition of a derivative. He began his lesson sitting at a table with just a few, and then more and more asked to join. The group eventually grew so large that they had to relocate and found an area with a chalkboard. As Messler continued, presenting examples and explanations on the board, more joined. By the time the lesson was over, he found that he’d essentially taught a class. Others took note of this, including the coordinator for a program that arranged for juniors or seniors to teach intro-level math classes. She offered him a teaching position on the spot, and he accepted.

Making Math Meaningful

Messler knows that one can acquire many life skills through math; everything students learn can be applied outside of the classroom.

“Math allows you to stretch your mind muscles, think logically, and systematically approach things. It not only strengthens your problem-solving skills but your critical thinking skills as well,” he says.

“Mr. Messler taught me that effort matters more than talent. He shows us that always trying our best and staying disciplined will take us further than our natural skills,” says Sadie P. ’27.

Thomas Insana ’16 agrees. “Mr. Messler was the best person,” says Insana, recalling how he was “accidentally” placed in his higher-level math class. “He said I’d do fine and kept me in the class. I proved myself in the first week, and I think I got one of the highest scores in the class.”

The most rewarding aspect of his teaching career is when his former students or parents of students come back and, with gratitude, share how much they loved his class and that they felt well-prepared for all that followed in their educational career.

“What still stands out to me today about Mr. Messler is how much he cares about our mastery of the subject and the relationships he has with his students,” says Alex Shapiro ’22, a junior at Saddle River Day School. “Between review games and 20-minute tangent conversations about a single problem, he prioritized our understanding of algebra over the pacing of the year. We didn’t finish a unit until every student understood it.”

“He is so proud of his students’ successes, so I always wanted to push myself,” Shapiro adds. “Running into him recently, I got to tell him how I now take AP Calculus BC as a high school junior and that it was because of the foundations he laid. High school math builds heavily off of topics we learned in middle school, and Mr. Messler made sure he sent us off strong.”

Beyond the Classroom

Messler loves taking on new challenges, even when he’s not teaching math. A firm believer that teachers should know students beyond the classroom, he dedicates his time to coaching and the performing arts.

“I did not seek out becoming a coach,” Messler says, “but I believe teachers and staff at independent schools should get to know students outside the classroom through extra/co-curricular activities. I value having the students see me as more than just a math teacher.”

Messler applies this philosophy to both the co-ed soccer and girls lacrosse teams. On the soccer field, he led the co-ed team to one of its best records in school history during the fall 2024 season. He finds it personally rewarding to work alongside fellow coaches Ian Glover, Andy Escala, and Gene Love, and loves seeing his students come together as a cohesive unit. For the girls lacrosse team, he notes that many players come to the sport with little to no experience, but what inspires him most is their willingness to embrace the coaching and the challenge to improve. Their positive attitude and enthusiasm, regardless of a game’s outcome, make coaching a meaningful and enjoyable experience.

“Mr. Messler’s coaching style is similar to his teaching style. He gives you valuable feedback that helps you become a better person, student, or athlete,” says Mason R. ’26.

Sadie P. ’27 agrees. “He is always encouraging, calm, and focused. In the classroom, Mr. Messler breaks down questions for us to understand easily, and on the field, he breaks down complicated drills the same way.”

“I always feel like in the classroom, he strives for us to become better masters of the many different mat concepts he teaches us, and I feel that same energy when I am out on the field. He truthfully wants his players to become better at playing, but also better at understanding the game,” adds Scarlett W. ’26. “He cheers on our team and motivates us to score at least one goal, even if the score is 0-11. No matter the situation, he is, without fail, going to try to help you improve it, not by doing it himself, but by teaching you how.”

“In seventh grade, I was tasked with playing goalie,” recalls Yael P. ’25. “Although the prospect initially felt daunting, Mr. Messler’s encouragement and fun personality made practices more enjoyable.”

Even with his coaching commitments, Messler finds time to participate in the performing arts. Although he was not involved in theater as a student, he deeply appreciates the time, dedication, and courage it takes to be in a school production. He is happy to wear a few different hats during the musicals and finds it impressive that middle school students are willing to step outside their comfort zones to be part of the musical each year.

Photo caption: From teaching problem-solving in the classroom to fostering resilience on the field, David Messler supports students as both an educator and coach.

Lasting Impact

With an adventurous nature, Messler will try anything from new foods to activities like spelunking and paintballing. Unsurprisingly, if he had to choose a motto, it would be “embrace challenges.’

Messler’s dedication to his students and his passion for math have helped make him a beloved member of EMS. He notes, having worked at many schools, that EMS is an exceptional place.

His colleagues couldn’t agree more, and many feel he is one of the reasons that EMS is such a special community.

“He creates a warm, positive atmosphere that makes people feel comfortable and heard,” says Morrow House math teacher Heather Ban. “Dave is always willing to share his ideas and teaching resources with no hesitation. When I first taught an Algebra course, Dave worked closely with me to list the units he was covering so I could align my course with his. He generously shared his entire Google Classroom, allowing me to view his pacing and course overview. This was incredibly helpful and gave me a strong foundation to build on.”

“Dave’s students truly love him and enjoy being in his math class,” Ban adds. “He grades assessments very quickly, and students appreciate the fast feedback, which helps them reflect and improve.”

Fifth-grade teacher Jackie Riley says, “As a coach, teacher, and colleague, Dave consistently goes above and beyond. He is generous with his time, always willing to step in and help wherever needed.”

“When alumni return to EMS, Dave is often one of the first teachers they seek out,” adds Riley. “A small crowd quickly gathers around him, diving into spirited conversations about high school or college math classes, or reminiscing about sports teams and shared memories. His students feel seen and respected. He meets them exactly where they are and challenges them to grow.”

“My favorite thing about EMS is the incredible community,” says Messler. “The faculty are not only talented and dedicated educators, but they also inspire a genuine love of learning in their students.”

And as his colleagues and current and former students can attest, Messler embodies the kind of educator he speaks of — one who makes EMS’s community so remarkable, inspiring students with his passion for teaching.