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.

Sierra Herrera

Center Director

Libby Lossing

Director of Marketing
Libby brings a dynamic blend of leadership, education, and community spirit to her roles as Director of Marketing at Mathnasium.

Prior to joining the Mathnasium team full time, Libby attended the University of California, Los Angeles, where she was the Captain of the UCLA Spirit Squad and traveled the country as the school’s mascot. This multifaceted experience allows her to connect with a wide range of people and fosters a collaborative and engaging atmosphere in her work. In addition to her bachelor's degree from UCLA, Libby holds a certificate in School Management and Leadership from the prestigious Harvard School of Education and Business School.

Some of Libby’s exceptional achievements include:

  • Best Overall Marketing in North America: Libby was recognized as the first ever recipient of this award because of her outstanding community and school engagement, media integrations with local news, and overall ambassadorship for the brand.
  • Best Assessment Improvement Award: In a franchise of over 1,000 learning centers, Libby’s location showed the best educational results for students overall.
  • Local Business Person of the Year: An award voted on by local business owners based on the value of the person’s contributions to their network.
A key member of the Mathnasium team since 2017, Libby is dedicated to creating a positive and enriching learning environment for all students.

Youngkun Weiss

Director of Operations

Karen Lossing

Executive Director

Carol

Instructor

Hello! I’m Carol Wall and I’ve been a private math tutor for 12 years, including 2 years as a private teacher for two competitive skiers in Vail, Colorado. I received a degree in marketing and advertising from Michigan State University, but always had a passion for numbers. I worked as a media buyer negotiating contracts for television and radio, and then as an account executive managing budgets. When 2 of my children were diagnosed with learning differences, I took time off from my advertising career to help them navigate school. I found I had a gift for teaching math to students with dyslexia, dyscalculia, dysgraphia and other learning differences. So, I started my own tutoring business and have been very busy for the past 12 years. I came to Mathnasium because most of my students graduated or were succeeding at math on their own. After an interview and trial day, I knew this place was for me! Getting to impact so many children’s lives by helping them make sense of numbers and understand how math is used every day in our world is very rewarding!

In 5 years I will be: Semi-retired as a math tutor and traveling to beaches around the world.

Fun Fact: I was a ski instructor while taking math and engineering courses at Michigan Technological University

Hobbies: Board game nights, Going to mountain town cabins to hike, explore and have campfires, swimming at our neighborhood pool in the summers, and trail riding on our three horses, Bentley, Sterling and Luna.

I love Mathnasium because . . . my passion is to figure out how a student learns best and watch them finally make sense of numbers and realize that math is a universal language.

Evan Lossing

Director of Human Resources

Steven Lossing

Executive Director

Jacob

Instructor

Hello my name is Jacob, I graduated from Colorado School of Mines with an undergrad degree in statistics in 2020. I have recently moved back to Colorado and am pursuing a masters degree online through the University of Florida. One of my goals is to help make math more accessible to people in their everyday life, and I believe that being a part of the mathnasium team will help to accomplish this goal.

Favorite Number and Why: 42, it is the secret to everything.

Favorite Math Joke: Teller: Why was 6 afraid of 7 Listener: I don’t know Teller: Because 7 ate 9. Teller: But why did 7 eat 9 Listener: I don’t know Teller: Because it is important to eat 3 squared meals a day

Fun Fact: I was not able to snap my fingers until my Sophomore year in college.

Favorite Math Topic and Why: Probability, it helps us to predict likelihood of events before they happen

Makenzie

Instructor

Hello, my name is Makenzie Sobieski! While looking at jobs for over the summer, I remembered seeing Mathnasium near my local high school, Columbine. I thought, “How cool would it be to help kids be as passionate about math as I am”. I have always been better at Math than English, so I decided this job would be a perfect fit for me. After shadowing other Mathnasium employees, I realized how awesome the atmosphere and culture at Mathnasium was and knew I had to take advantage of the opportunity. I think my favorite part about being an instructor is seeing the vast improvement in not only kids’ math skills, but also their love for math. Math can be a very tricky subject, but once understood, it is sure to be a favorite.

Favorite Number: My favorite number is 7 because it has been my softball number for my entire 10-year career and it is also my bunny, Phoebe’s, birthday.

Favorite Math Joke: Question: Why did the obtuse angle go to the beach?

Answer: Because it was over 90 degrees.

In 5 years, I will be . . . Graduated from the Colorado School of Mines with a Civil or Biomedical Engineering degree.

Fun Fact: I’m an identical twin.

Hobbies: Competitive softball, hiking and traveling with my family, and spending time outdoors.

Ariana

Instructor

Hello! I am Ariana and I am a sophomore at D'Evelyn Jr./Sr. High School. In elementary school, I struggled with English as a second language, so math immediately became my favorite subject because it is globally taught and understood. Mathnasium is a very welcoming place where I love to spend time working with different kids and help them improve their math skills. In my free time, I like going to the mountains, dancing at my studio, and spending time with friends. After high school, I plan to study some sort of engineering in college.

Hobbies: Snowboarding, drawing, dancing, listening to music.

Fun Fact: I speak three different languages.

In 5 years I will be . . . traveling throughout Europe.

Favorite Number: I like the number 8 because it is an infinity sign flipped.

Hank Jarboe

Instructor

Hi! My name is Hank Jarboe. I've been teaching for the greater part of ten years, whether it be in a public school setting, tutoring one-on-one or even at the skatepark. I truly believe that most problems can be solved through education, understanding and learning, and one of the tenets of being a great educator is being a good learner. I love teaching, but my personal daily miracle is learning from my students.

Favorite Number: My favorite number is 5! For some reason, I associate 5 with the color green, which is also my favorite color. I also love 12, because it's so divisible!

Fav Math Joke: Mixing French and math, my favorite math joke involves a French cat named Un Deux Trois (or One Two Three in English). Un Deux Trois wants to sail across the English Channel, but his boat is no good. Unfortunately, the Un Deux Trois cat sank (which is a pun for counting to 5 in French: Un Deux Trois Quatre Cinq)

Fun Fact: After years skateboarding as a kid (and not being very good at it), I've tried picking it back up at 30. Fortunately, I've only suffered one broken bone since then, but I've made tremendous strides in tricks and my own personal confidence, on or off the board. I also love to help teach kids while skating.

Zach

Assistant Center Director

Hello, my name is Zachary and I have been an instructor at Mathnasium of Littleton for 7 years, all the way back to when I was just 15! Besides my passionate love for mathematics & teaching the subject, I enjoy many things. Throughout the year, I play Ultimate Frisbee. In addition, I love to travel, whether it be to Europe, Mexico, Washington D.C., Moab or Glenwood Springs. I traveled to Mexico five years ago to help with a Habitat for Humanity project. In my free time, I enjoy solving logic puzzles, like Sudokus or one of my Rubik's Cubes. I've always loved working with kids and have always enjoyed math so sharing my knowledge with students at Mathnasium is a perfect fit.

Favorite Number:  My favorite number is 1729. There was a man named Srinivasa Ramanujan who was a famous mathematician in the early 20th century. Despite growing up in India and having very limited access to the mathematical knowledge of the time, he taught himself and was sought out by English mathematicians for his work in all fields of math. A colleague and friend of his, G.H. Hardy, visited Srinivasa in the hospital and mentioned that his taxicab number, 1729, was an unusually dull number. Srinivasa remarked that in fact, it was not. 1729 is the smallest number that can be written as the sum of two cubes in two different ways, 10^3+9^3 and 12^3+1^3. Nowadays, 1729 is known as a taxicab number for this exact reason. Additionally, the sum of the digits, 19, times its reverse, 91, gives you back 1729. These types of interesting facts that you can find for every number show the true beauty in mathematics.

Favorite Math Joke: Why do mathematicians always get Christmas and Halloween confused? Because Oct 31 = Dec 25. In base 8 (Oct), the number 31 is the same as the number 25 in base 10 (Dec or Decimal).

Fun Fact: People at school and in the Ultimate Frisbee community call me Steve due to the fact that there were two people named Zach on our high school frisbee team. I received the name Steve and the nickname has stuck ever since.

What is your dream? Living in Spain with an enjoyable career and becoming fluent in Spanish.

Michael

Lead Instructor

Hello, my name is Michael. I am a graduate of the University of Colorado in Colorado Springs with a bachelors in mathematics. I have been a college tutor and have worked in an elementary school for five years. I have worked at Mathnasium for 3 years now. I wanted to work at Mathnasium because I enjoy helping people out with concepts and topics that are causing them stress or difficulty. The atmosphere and the vibe Mathnasium gave off was fun and inviting, so naturally I wanted to be a part of the team. I also enjoy working and interacting with kids. I remember tutoring and holding study sessions for a majority of my college algebra class. The experience was fun, plus it was a good feeling to be able to help my fellow classmates not be super stressed out about math. The teacher noticed I was doing these things and after the class was finished, helped me get a job as a tutor at the school's learning center. I hope to use my talents and personality in order to help students be the best they can be. In addition, I want to help them build confidence, not only in math, but in their everyday life as well.

Favorite Number and Why: ​18 because it's cool (and it's my birthday)

Favorite Math Joke: Are monsters good at math? Not unless you Count Dracula.

In 5 years I will be . . . . teaching math.

Fun Fact: I used to play video games competitively.

Adrian

Instructor

Hello! My name is Adrian and I am currently a senior at Metropolitan State University of Denver majoring in chemistry. My family is from Guatemala but I am a Colorado native. I prefer Colorado’s cool dry air to Guatemala’s hot humid climate any day.

Ever since I was a kid, math and science were always my favorite subjects in school. Math and science go hand in hand with each other because they both are used to interpret and understand the world we live in. Throughout my life I have been told by many people that I would be a great teacher as I am very kind, optimistic, and patient. It is important to me that students feel supported as they progress through their academic careers and that they learn to celebrate their successes, even the little ones. My dream job is to be a chemistry professor. I decided to work at Mathnasium because I believed it could give me valuable teaching experience. Working with a variety of students of all ages has helped me to be creative and find new ways of explaining academic topics.

Favorite Math Joke: Why did the mathematician spill all his food in the oven? The directions said, “Put it in the oven at 180°”

In 5 years I will be . . . . In graduate school pursuing a masters degree in physical chemistry.

I love Mathnasium because . . . . . Of the support system. I really value the care and effort Mathnasium puts towards creating a comfortable judge-free learning environment. I love helping students build their confidence in math and make them feel supported.

Hobbies: I love games! Video games, board games, card games, you name it! When I’m not playing games, I enjoy going to the park to walk my dog. In summer, I enjoy hiking and going on camping trips with my family.

Favorite Math Topic and Why: I really enjoy taking derivatives of functions. The concept came easy to me and it was my favorite thing to do in Calculus. Partial derivatives are fun too!

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.

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

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!

Explore Employment Opportunities