Our staff is built to teach each student individually, to develop the skills they need to thrive in mathematics, and to foster a love of learning.

Yesenia Castelan

Educational Director

Yesenia has loved math and science since childhood, participating in STEM activities and tutoring students throughout her school years. After earning her degree in Biomedical Engineering with a minor in Spanish & Hispanic Studies, she began tutoring Algebra and Pre-Calculus to college students and found deep fulfillment in supporting their success. 

She enjoys keeping lessons fun and interactive, so students stay motivated and confident. Yesenia believes every student can thrive in math, and she takes pride in helping them build both skills and a lasting appreciation for the subject. 

Sam York

Educational Director

Sam has always been a Math-minded individual, skipping a couple grades in school, and turning his passion for sports into an obsession with statistics and data. It was through sports that his love for helping others and working with children grew. As a member of his high school basketball team, Sam received a coaching certification, and would regularly attend and run camps for younger athletes. At this same time, he got into private tutoring, turning his knack for aiding his classmates with homework into a more serious endeavor. It was during his time at the University of Georgia, that Sam realized his abilities in the field could become a career.

Since moving to New York City, he has now worked with Mathnasium for the better part of 3 years, and continues to grow as an educator, mentor, and leader. In his free time, you can probably find him at the gym, playing tunes with friends, or losing his mind over fantasy football. Sam is a firm believer that anyone can boost their proficiency, and better learn the language that is Mathematics. He is thrilled to continue to be a part of each student’s journey in doing so.

Sabahat Rahat

Educational Director

Sabahat has had a passion for mathematics from an early age, inspired by the teachers and professors who nurtured her understanding of the subject. While earning her degree in Computer Science, she recognized the challenges many students face with math and began tutoring to help make the subject more approachable. She later joined Mathnasium as an instructor, where she is dedicated to helping students build confidence, achieve clarity, and develop an appreciation for mathematics. Over the years, she has witnessed countless “aha” moments—students moving from reluctance to genuine interest in learning math. Sabahat remains dedicated to fostering these breakthroughs and to cultivating a lasting appreciation for mathematics in all her students.

Our Mathnasium Mission

Teach children math so they understand it, master it, and love it. Math can change their lives, and they can change the world.

Quote Quote
What I love about Mathnasium is the ability to teach problem-solving skills and make math make sense, while also making a student smile.
Amber W., Mathnasium Instructor

Schedule Your Math Skills Assessment Today

Student using math cubes to solve fractions
Student working with a math tutor at a local math learning center

Want to join the Mathnasium team?

Are you interested in changing lives through math? We're looking for outstanding individuals with a high level of commitment who are passionate about teaching math. Find out if there's a Mathnasium position that's just right for you!

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