Mathnasium 11211 Dransfeldt Road, #149, Parker CO 80134 (303) 840-1184

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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:

 Rachel Geyer, Center Director

Short Bio: 
Hi, my name is Rachel Geyer.  I've lived most of my life in Colorful  Colorado and graduated with my BA in Education from Colorado  Christian University and my Masters in Curriculum and Instruction from  the University of Phoenix.
Why I Love Working at Mathnasium:
During my first year of teaching I discovered a  passion for helping elementary students understand numbers and how  the apply them to every part of our lives.  I love it when a student who  professes to hate math start to complain that math time is over and begs  to keep working!  
I live in Aurora with my husband and our three silly dogs.  
In my free time, I enjoy spending time with my family and traveling.  Recently we took a trib to Moab, Utah to travel the back roads and take a hot air balloon ride.  Here in town, we love riding our bikes and discovering new fun places to eat. 
Nick Lehnertz, Assistant Director 

Short Bio:

Hello! I am Nicholas Lehnertz. I grew up in Gilbert, Arizona and graduated from Arizona State University this past Spring with my Bachelors’ degree in Aerospace Engineering (Astronautics). During my education, I played the bass trombone and participated in marching band all four years of high school and went on to march as a member of Drum Corps International. I decided to move to Colorado with my girlfriend, Stephanie, and our dog, Olive, a few months ago because it is much prettier and MUCH less hot than Arizona. I am currently looking into continuing my education and starting a Masters’ degree in Mechanical Engineering at CU Denver this coming Spring.

Why I Love Working at Mathnasium:

I worked at a summer camp in 2016 and found that I really enjoyed working with young students. This + a love of math = loving every minute of working here!

Favorite Math Joke:

Q: Why was 6 scared of 7?

                A: Because 7, 8, 9. 

Q: Why was 23 scared of 24? 

                A: Because 24, 25, 26.

Hayden Steinemann,  Mathnasium @Home Instructor

Short Bio:

Hey! I am Parker born and raised. I went to Ponderosa High School and spent a year at the University of Kentucky to study Civil Engineering. I found out that Kentucky wasn't where I wanted to be and that Engineering wasn't what I wanted to study so I've come back to Colorado for a gap year and to decide what major I want to pursue in my future. 

Why I Love Working at Mathnasium:

I love Mathnasium because it allows instructors to focus on a student's individual needs and preferences. The small group style of teaching lets us instructors get to know each kid and learn how they respond to different teaching methods and strategies for solving problems. (and honestly the kids can be really funny sometimes)

Favorite Number:

My favorite number is 2, because you've got a 50/50 chance of being able to divide by it.

Favorite Math Joke:

Q: How do you know if a math major is flirting with you?

                A: They ask what your sin is.

Math Story:

I wasn't always good at math. I've always struggled with ADHD and because of this I had a really hard time learning in class. I can remember really struggling in math during elementary/middle school and thinking that I could just never reach the same level as the other kids. The summer before my freshman year I decided to start going to a tutor to help me re-learn all the things I had missed in class and it paid off big time. I started succeeding, in a subject I had thought was a lost cause for me, because of the confidence I built up over the summer. I ended up passing all my math classes with straight A's and earning multiple academic scholarships by the end of high school.

Favorite Math Topic:

My favorite topic in math has always been algebra. Its kind of like the bedrock for all other higher math and the skills you learn from studying it are, in my opinion, probably the most used in the real world.



Barbara BennettBarbara Bennett, Instuctor

Short Bio:

Hello, I’m Barbara DeHaven Bennett. While I’m not a Colorado native , I have spent most of my life in this beautiful state.  I attended Bear Creek High School, Metropolitan State University of Denver and the University of Colorado at Denver.   I have two Bachelor’s degrees (Mathematics and Psychology) and a Master’s Degree in Secondary Curriculum and Instruction with a focus on Secondary Mathematics.

Why I Love Working at Mathnasium:

For twenty-nine years, I had the privilege of teaching high school math in Denver.   During that time, I worked with a wonderfully diverse group of students that came from over forty different countries and spoke over sixty languages.   There is nothing like the sparkle in a child’s eye when they have that “aha” moment of understanding.  Mathnasium provides both the students and me with the opportunity to experience that “aha” moment everyday.

Favorite Number:

Any number that is a palindrome - I love the symmetry!

Favorite Math Joke:

The only way for me to explain to our students just how delicious a big Holiday meal is, is by writing: 


I enjoy golf, skiing, reading, scuba diving, traveling and of course, math! In recent years I’ve had many wonderful travel opportunities including a tour of London and Scotland, and scuba diving trips to Mexico, Grand Cayman, and Hawaii. My favorite was the London/Scotland trip which included dinner in the Tower of London, a private viewing of the Crown Jewels and a round of golf at both St. Andrews and Gleneagles. 


Ashi Sood,  Lead Instructor

Short Bio:

Hi! My name is Ashi Sood. I’m a senior at Legend High School, where I participate in Student Government and am also a part of Legend’s golf team! 


Apart from math and science, some of my interests include drawing and painting, playing the piano, and spending time with my family in India. I have an absolutely adorable golden doodle named Timber who acts as my personal foot-warmer throughout the cold Colorado winters.

Why I Love Working at Mathnasium:

I enjoy working at Mathnasium because I actually attended Mathnasium in 3rd grade as a part of the enrichment program. Now, I’m on the other side of the table and love seeing the kids grow confident in their math skills!

Favorite Math Joke:

Q: What do you call friends who love math?

                A: AlgeBROs

Sophie Whitehead, Instructor

Favorite Math Joke:

Q: What’s a math teacher’s favorite kind of tree?

                A: Geometry!

Fun Fact:

I have participated in the Colorado State Spelling Bee three times!


In my free time, I enjoy playing with my dog, Coco, playing the piano, reading books, spending time with my family, and exploring Denver! 

Favorite Math Topic and Why:

My favorite math topic is solving algebraic equations because you can check your work to make sure you came to the right answer. It always feels rewarding to solve a complicated equation. 

Your Story - Why Did You Come to Work at Mathnasium?

I have always loved learning math and wanted to share my love for the subject with others! My goal is to make math fun and understandable so that kids can enjoy it as much as I do. 

Dawson Kern, Instructor

Favorite Number:

8, because it’s a power of 2 and one less than a perfect square.

Favorite Math Joke:

There are 10 types of people in this world: those who understand binary and those who don’t.

I Love Mathnasium Because...

It lets me do math, which I love, and help people out, which I also love. I really enjoy watching students go from struggling with a concept to being able to completely understand it and explain it to someone else.


In my free time, I enjoy reading and doing math. I also occasionally do some coding and play games with my younger sister.

Favorite Math Topic and Why:

I really like algebra because everything just comes together at the end when you solve it. For example, with systems of equations, you can easily check your result and see how you got what you did, which makes it that much more fun to solve.

Your Best Math Story:

My younger sister was never as interested in math as I was, but I would still sometimes explain things to her when she thought of a new question or was wondering how to do something beyond what her homework explained. After a few months of this, she announced that she had tested out of the next grade level in math because of what I had taught her. This was my first big experience helping someone with math, and I’m very proud of how it turned out.


Allison Shride, Owner 

Short Bio:

I grew up in a family with a long line of entrepreneurs. I graduated from Colorado State University with a degree in mathematics and a teaching certification. Instead of using my teaching qualifications, I followed in my family's footsteps of being business owners and opened a retail store in Fort Collins at the age of 22. I stayed in retail for many years before transistioning to the world of wholesale which I was in for 16 years. I have also spent some time in the real estate arena, as well as some time spent as a scuba instructor in my younger days!

While these careers were all strong and profitable, they did very little for my heart space and I started searching for something else. I discovered Mathnasium and it was a perfect fit. I have loved helping children with their understanding of math, and witnessing their increased confidence and self esteem! I opened Mathnasium of Parker in January 2012 and we've helped hundreds of children. I love coming to work each day and seeing and hearing the growth our students are experiencing!


I have one daughter who graduated from Legend High School in 2012 and has gone on to graduate from  Colorado School of Mines. I was a very active and involved parent while she was in school, so I know many of the challenges and rewards that a parent in our school system faces.


I have a deep love of animals and I enjoy spending my spare time with my 3 rescue dogs. I used to have two dogs who were certified "pet therapists." We spent many hours visiting hospitals to share some canine love with the patients.   My newest dog and I are enjoying dog agility classes where she is developing her confidence learning to navigate various obstacle courses.


I have always loved traveling, and have recently discovered my new favorite way to see the world - long distance cross-country walking trips.  My first trip was through part of Tuscany, Italy for about 60 miles.  I have also traveled to  Scotland  and walked/hiked through the highlands for 92 miles in 6 days.   While not a walking trip, I had a life-impacting trip to India.  I spent time in orphanages as well as a center for abandoned adults/seniors.  I did get some walking in though, as my trip wrapped up with a few days of hiking and camping in the Himalayas.  

 Watch this video to hear from some of the instructors at Mathnasium of Parker.