After School Singapore Math Classes

Small Group Classes based on the Singapore math curriculum

Balanced and Rigorous Curriculum

Why Singapore Math

We adopt a balanced math curriculum based on the Concrete-Pictorial-Abstract Singapore math pedagogy. Using strong visualization and modeling, we emphasize Logic Reasoning, Early Algebraic Thinking, and Problem Solving. Our goal is to establish a strong mathematical foundation in our students so that they would enjoy challenging math tasks.


Abstract concept is first introduced using physical, interactive concrete objects, e.g. counting objects


Students use visual representations of concrete objects to model problems, making them easier to comprehend


Students understand concepts at a symbolic level, e.g. using symbols for mathematical operations and algebra

Congratulations to our students on their fine achievement in the CML 2020-2021

Our Grade 4, 5, 6 and 9 teams are Regional Winners in the CML 2020-2021 competition season! Massachusetts is in Region 1, which is our New England region. It includes: CT, MA, ME, NH, VT, RI.

Why Parents and Students Like Our Program

Conceptual Understanding

It is not just about learning algorithms and procedures but understanding why they work.

Problem Solving

Being able to use the toolsets to solve novel multi-step problems you have not seen before.

Small Group Sizes

Group sizes are small to ensure individual attention and class participation.

Qualified Teachers

Caring and experienced teachers that encourage class discussion and support learning.

Find Out More About Our Program

Sign up for a FREE evaluation to see if our program is a good fit!

Lesson Structure

Each week’s lesson consists of two parts:

Foundational Math

Focus on conceptual understanding and procedural fluency. Topics are taught linearly and circled back the next year, promoting deeper understanding.

Problem Solving

Students are exposed to unfamiliar problems every week, requiring them to deeply comprehend the problems and organize to problem-solve.

For my son, the additional reinforcement of math principles that Singapore Math is so important for his memory, processing ability, and math confidence. Ms. Jean is a terrific teachers who my son both respects and genuinely enjoys learning from. I wish she was in his classroom every day!

– Parent of 2nd Grader

We like the small class size, and teachers providing feedback about my child when necessary especially when I can also help, CML problems and meets, the active involvement of the owner Kar Hwee, which has maintained and improved the quality of instruction over the years!

– Parent of 4th and 7th Graders

Love the practical application of math in the problems presented. It’s not just about learning how to compute a calculation, but how to think through what the word problem is asking and how to apply math (and which tools) to the solution.

– Parent of 6th Grader

Our Journey

Our program started in 2015 in our dining room. Over the years, we have build a strong team of teachers and have helped many students build strong mathematical foundation and learn to enjoy math.


In-Person and Remote Classes


Experienced Math Teachers


Happy Learning Students

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Our Teachers

  • Kar Hwee Koh

    Founder & Teaching Principal

  • Kevin Yan


  • Lydia Eldridge


  • Janet Keefe


  • Rana Razi


  • Rowena Jimenez


  • Indira Bhupatiraju


  • Chandan Keshkamat


Kar Hwee Koh

Founder & Teaching Principal

Kar Hwee Koh, Ed. M., has been teaching Singapore Math® in schools in Singapore before relocating to Lexington, MA. She started Lexington Singapore School through encouragement from her family, friends and neighbors. She believes in setting high expectations for her students and nurturing creative and confident math problem solvers. Apart from running the after school program, Kar Hwee also conducts teacher workshops and is a frequent presenter at National Math Conferences.

Recent Presentations at Workshops and National Conferences
  • Certified Teacher in both Massachusetts State and the Republic of Singapore
  • Advanced Master of Education (Ed.M), Columbia University Teachers College, GPA 4.0
  • Master of Education, University of Western Australia, Higher Distinction
  • Postgraduate Diploma in Education, National Institute of Education Singapore, Distinction
  • Bachelor in Electrical Engineering, National University of Singapore, Honors

Kevin Yan


Kevin holds a Bachelor of Science in Psychology from UMASS Boston and is currently pursuing his Master of Education in Middle/Secondary Education at UMASS Boston. After receiving his B.S., he served with AmeriCorps in urban education services, prompting him to pursue a career in mathematics education as he personally witnessed a shortage of qualified teachers. From then on, Kevin taught and developed curriculum for various education programs and institutes within Boston, Greater Boston, and the South Shore. As a pedagogical preference, Kevin emphasizes visual learning techniques, responsive classroom approaches, and game-based learning to ensure that students are learning effectively. In his free time, Kevin enjoys comics, manga, and video games, and is a passionate UFC fan.

Lydia Eldridge


Lydia Eldridge is from California where she got her a bachelor’s degree in Conservation Biology. Currently pursuing a graduate degree in Environmental Health Engineering, she is passionate about equitable STEM education and enjoys getting people excited about math and science. She has had the opportunity to work with and teach middle school students from all over the greater Boston area, in traditional classrooms and even on an island! In her teaching, Lydia emphasizes the practical aspects of math and highlights how skills learned can be applied to everyday life. In her free time, she enjoys hiking, reading, and working in her garden.

Janet Keefe


Janet Keefe has a Bachelors Degree in Mathematics from Assumption College and a Minor in Elementary Education. She has a diverse background teaching children of all ages from Grade 1 to Grade 12 Calculus. During her college years, she worked at Nelson Place Elementary School in Worcester, MA as a Teachers Assistant aiding Elementary classes in all areas, including children with ABA, Autism, and Non-Verbal learning challenges.
Janet likes to make the classroom experience fun, including virtual learning, by engaging students to show their work, working as a team, and on occasion bringing in her guitar! She currently works full time doing Marketing as her other passion and skill set. When she has free time, Janet enjoys skiing and snowboarding. Janet is currently attending Graduate School, at Babson College in Wellesley, MA, looking to obtain her Babson MBA in Entrepreneurship and Marketing.

Rana Razi


Rana Razi has been teaching math at various schools for the past ten years. Prior to switching to the field of education she had worked as an engineer in the Boston area. Her goal is to make math a more enjoyable subject for students. Currently she is working at Boston Public Schools.


Bachelor of Science in Electrical Engineering from Boston University

Master of Arts in Teaching Mathematics grades (5-12) from Western Governors University

Teaching certification for teaching math grades 8-12 in Massachusetts and Oregon

Rowena Jimenez


Rowena Jimenez received her MA in Urban Policy from Tufts University (focus on education issues). She has taught elementary level students since 2010, and is currently a 4th grade teacher in an Independent School in Boston. Prior to that, she worked as a certified Middle School Math teacher in public schools in Lowell Ma.
Founder and Executive Director of a literacy nonprofit that builds engaged learners and change agents in an underdeveloped nation, Ms Jimenez believes that meaningful knowledge is organic and students of any age learn excitedly and effectively about anything that is of consequence to them. The educator’s role is to facilitate learning by creating an environment that nurtures inquisitiveness and collaboration. She recently finished a 13-week professional development course offered at Harvard called: Teaching and Learning in a Maker-Centered Classroom as part of her nonprofit work in the Philippines. She currently supports teachers in the Philippines offering non traditional learning experiences online for children in poor communities there, including math that’s based on the Singapore math philosophy.

Indira Bhupatiraju


Indira Bhupatiraju has a Master of Education in Middle School Mathematics from Lesley University in Cambridge, MA. Indira has worked in Elementary/Middle schools as an Instructional Assistant and as a Teacher for more than 12 years. She enjoyed working with both Elementary and Middle school students and she earned a DESE Certification for Elementary and Middle School Mathematics for teaching. She strongly believes that every student can excel in math given right support and guidance by the teacher and enjoys working with children. She is passionate to teach concepts, sets high expectations for students and encourages them to try hard. She is currently working as a Middle School Math Teacher.

Chandan Keshkamat


Chandan received her Master of Science degree from Goa University, India with top honors and ranking 1st in her college. A devoted mother, teaching is her passion and she loves working with students at all grade levels. She holds Massachusetts Teacher’s License to teach students in Grade 5 to Grade 12 and has been working as Teacher/Substitute Teacher/Exceptional SAT tutor at both public and private organizations such as Neighborhood Charter School-Boston, High Expectations, LLC. Malden, Huntington Learning Center-Waltham and Tutor Doctor tutoring agency.

Our Center

We are located right in Lexington Town Center, behind the Cary Memorial Library. Street and meter parking is available around the area and in the Town Municipal Parking Lot across the street.


19 Muzzey Street, Suite L40, Lexington MA 02421


Tel: 781-479-2331

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Lexington MA

19 Muzzey St,
Suite L40,
Lexington, MA 02421.
United States.

Acton MA

271 Great Rd,
Suite 26,
Acton, MA 01720.
United States.