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Our Team

Our specially trained math instructors will teach your child how to understand math in an individual setting; our unique approach enables us to explain concepts really well and lend a helping hand to every student. Our tutors foster a caring, encouraging environment that helps kids thrive and learn! Read below to learn more about our talented team:

Youngkun, Center Director

Youngkun is customer service driven and has a passion for teaching math.  The desire to help make "math make sense to kids" is what brought to Mathnasium in the first place. Youngkun offers outstanding consultative advice to educate parents and students on the Mathnasium program and the academic expectations of kids today with Common Core standards. Knowing success breeds success, Youngkun's team will help design a learning plan just right for each student so they can meet their math goals in an efficient manner. You can always schedule a time to meet with Youngkun to discuss your student and their mathematical progress by clicking


Jeremy, Assistant Center Director

Jeremy is a math major at Cal State San Marcos. He is a TA on campus for his peers and an a valuable asset to our center - teaching math in a manner that makes sense to younger kids through Calculus! Having worked at another Mathnasium prior to joining us, Jeremy's knowledge bank on the problems, techniques and strategies of the Mathnasium Method and expectations from school make him an incredible addition to our team.



Aesher, Lead Instructor

Aesher holds a Bachelor's in Environmental Science and an MS Environmental Policy and Management from American Military University. He plans to continue his education further by earning a EED in Higher Education with a focus in STEM and an MBA. He has experience tutoring English, Math, Chemistry, and Biology for over a decade and relocated to the community after having worked at another Mathnasium in Orange County. Aesher makes math fun by utilizing everyday situations into math concepts.

Clair, Lead Instructor

Clair is going into her third year at Miramar College where she is pursuing a major in Interior Design. Clair excels at breaking down Algebra and Geometry concepts for our middle school students. She works hard to make learning math an enjoyable time and it shows in the smiling faces of the kids she spends time with.



 Anton, Instructor

Anton recently graduated from high school and will be attending Palomar College in the fall. While new to Mathnasium, he is no stranger to tutoring young children, as he has previous taught kids Russian. In his free time he enjoys acting and working on plays and musical theater productions. Anton is passionate about math and making learning an enjoyable experience with real world applications.  

Brianna, Instructor

Brianna is a Junior at Del Norte High School. She is very accomplished in math, scoring a 1530 on the SAT, successfully completing AP Calculus AB as a sophomore, and she is currently taking AP Calculus BC. In addition to her love of mathematics, Brianna also has a passion for other subjects both in the humanities and sciences; and has taken AP Biology, AP Chemistry, AP European History, AP English, and AP US History (at Palomar College).

Brianna's combined love for kids and math makes working as an Instructor a dream job for her. Math can be a very frustrating subject for many people and helping students build their confidence in their mathematical abilities is extremely rewarding. Brianna spends most of my time at Mathnasium instructing middle school and high school students in algebra, geometry, trigonometry, and calculus.


Shireen, Instructor

Shireen Tango currently attends California State University San Marcos. She is in her third year of college working on a major in Biotechnology, with a minor in Music. Shireen has finished rigorous college math courses, such as Calculus, and enjoys Algebra and Pre-Calculus because she finds the concepts fun.

Shireen's love for math began early on in middle school when she started to realize that there are so many different ways to reach an answer to different math problems and equations. She brings her experience from working with children in the past, and loves being able to teach math to the students here at Mathnasium and being able to watch the students faces light up because she observes firsthand the methods we teach and use give confidence to many students enrolled here.

Outside of my academics I am on the Improv team at my school. I also enjoy spending time outdoors such as going to the beach and hiking.

Danikko, Instructor

Danikko (a.k.a. DK) is a Senior at University of California, San Diego pursuing a degree in Electrical Engineering. While as UCSD, Danikko has taken advance math courses such as Vector Calculus.

DK enjoys working with our Mathnaisium students because it combines him love of math and the fun of working with kids. He has experience working with kids from his past when he coached a Youth Group basketball team.

In addition to math and basketball, another passion of DK's is building custom desktop computers.

Maryam, Instructor

Maryam is a Junior at California State University, San Marcos studying Management Information Systems. She holds an AA in Business Administration from Palomar College and is currently working on obtaining Real Estate License. During her schooling, Maryam has taken advanced math course such as Calculus I, Calculus II, Discrete Mathematics, Statistics, Linear Algebra, and C++.

Maryam is passionate about teaching math because: 1) She loves children; she used to work at the Boys and Girls club as a Summer Program leader and has a big family with lots of siblings; and 2) Math has always made sense to me and it keeps her mind sharp.

Outside of Mathnasium Maryam enjoys spending time with family and friends, hiking, and spending time at the beach.



Jessica, Instructor

Jessica is a second year student at California State University, San Marcos, majoring in chemistry with a minor in psychological sciences. At CSUSM she is the vice president and co-founder of Vietnamese Student Association and holds the media/tech chair in Circle K international. Jessica's studies have led to her taking advanced math courses such as Pre-Calculus, Calculus 1, and Statistics.

Jessica likes teaching math because she loves the subject and the students make it even more enjoyable. To Jessica, math is a universal language that everyone can understand unlike a word that can mean something in one language but something else in another.

When she is not at Mathnasium, she like to spend my time with friends or learn new things.

Anne, Instructor

Anne is an alumna of Westview High School (2012) and a graduate of the University of Oregon Robert D. Clark Honors College (B.S. Psychology, 2016). She is currently taking computer programming classes at San Diego Miramar College for a certificate before moving on to a Ph.D program.

In college Anne took math up through Calculus II, Discrete Mathematics II, and multiple statistics courses. She joined our Mathnasium team because she developed a love of math early on and being able to share that with others while simultaneously preparing them for the future makes her love this job.

Outside of work, Anne enjoys outdoor and athletic pursuits such as hiking and surfing.


Shawn, Instructor

Shawn is currently a Senior at Del Norte High School. He has experienced many notable accomplishments in math, such as scoring a 1530 on his SAT, a 34 on his ACT, an 800 on Math 2 SAT Subject Test, and successfully completing AP Calculus BC (5/5 on both AP Calculus Exams) and AP Statistics.

Teaching others has always been a passion of Shawn's. Being able to be an instructor at Mathnasium is perfect for him because it allows him to grow in his favorite subject but also as an instructor under a formal setting.


Grace, Math Beast

Grace is currently a junior at High Tech High North County. She began as a student here at Mathnasium. But soon wanted to expand my passion for math from learning to teaching. She has always been a big fan of math, and loves working with kids, as she has been a camp counselor for many years now. Grace loves being able to help students learn and grow in their math skills, just like she did.

Outside of her job, Grace loves the performing arts, especially musical theater.



Edward, Math Beast

Edward is a Senior at Del Norte; he has completed Calculus AB, Calculus BC, and is currently completing AP Stats. He hopes to pursue a degree in Computer Science at Carnegie Melon in the Fall.

In his free time, when he isn’t at school or Mathnasium, Edward enjoys playing the Chinese violin. He is passionate about teaching our young learners about math because he believes it is the keystone to success in many future fields of study.


Fox, Math Beast

Fox is currently enrolled in AP Calculus AB, and is planning to be a math/chemistry major in the future.

Fox enjoys his role as a Mast Beast at Mathnasium because it offers him the opportunity to practice his teaching skills. Fox jokes that sometimes he feels like he is the one learning because of all the unique ways he has seen kids approach a single problem. Fox's favorite part of the job is being able to see a kid push their knowledge of a topic to solve complex problems. It makes him happy when another kid carries on the flame of passion for math/any subject in general.

When Fox isn't busy with work or school, he like to play the piano and self-teach myself Chemistry and Mathematics.


Karen Lossing is the center director/owner of the math learning center Mathnasium of 4S Ranch.

Karen Lossing, Owner

Karen earned a Bachelor's degree in Marketing from Penn State and spent ten years in the business community. After staying home with her kids, she earned her Texas teaching certification and went on to teach third and fifth grades and Special Ed for seven years. In addition, she served on the Response to Intervention team and was a district liaison for Math Curriculum and Instruction. Karen completed her Master's degree in 2010 and, prior to moving to San Diego, served three years on her elementary school's administration team incorporating and facilitating 21st Century learning standards. Karen looks forward to math making sense to all the kids who learn at Mathnasium of 4S Ranch.

Libby, Director of Operations

After a couple years of being a seasonal instructor in our center, Libby graduated from UCLA in 2017 and has joined our team as the Director of Operations. While she is no stranger to the instruction and educational aspects of Mathnasium, Libby focuses on back office functions and the community involvement side of our center. So if you have any school events or sponsorship opportunities you would like Mathnasium of 4S Ranch to be involved in, Libby is your girl!