Private Tutor — Lester

Teaching Students
to Think,
Not Just Solve

JC H2 Mathematics Specialist — tutoring since 2003, starting during university years. Patient, conceptual lessons for Secondary, JC, Polytechnic, and University students, in Singapore and online worldwide.

20+ Years Experience
50+ Students Taught
10+ Current Students
O Level E & A Maths JC H1/H2 Mathematics Real-World Mathematical Thinking
Let's Talk Our Philosophy
Lester — Private Mathematics Tutor
NUS · Georgia Tech
Significant Grade Improvements
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Philosophy

What is Radical Simplexity?

Simplexity is the clarity that emerges only after genuinely understanding complexity — not simplification that loses depth, but the insight that becomes visible once you see the structure beneath.

Radical means a breakthrough idea that actually works. Not just different — tested, refined, and proven in practice. When the conventional approach is not reaching a student, we find the one that does.

Radical Simplexity is the drive and ambition to making mathematics clear, visual, and transferable — by going deeper, not by cutting corners — and to understanding the emergent clarity, behaviours, and patterns of mathematics.

In practice: helping students move from following steps to understanding why those steps work, so they can reason through problems they have never seen before.

Structure over steps — see the logic behind the method
Transfer, not memory — apply concepts to questions you've never seen
Beyond the exam — Mathematics as the thinking tool of life, and the learner's superpower for life
Lester — Radical Simplexity
About

Why Lester?

Patient, conceptual, and genuinely invested in every learner's growth

Caring & Encouraging

I create a genuinely supportive space where students feel safe to make mistakes and ask questions freely — without pressure or judgement. Rebuilding confidence is just as important as getting the right answer.

Friendly & Approachable

Students often tell me I don't feel like a typical tutor. Lessons are warm, conversational and low-pressure — making it easier to stay curious, open up, and engage deeply with the material.

Trustworthy & Professional

With 20+ years of experience, qualifications from NUS and Georgia Tech, and a consistent track record of significant grade improvements — students and parents can rely on a structured, proven approach to learning.

I help students move beyond memorising steps to genuinely understanding mathematics — and that shift makes all the difference in exams and beyond.

With more than 20 years of tutoring experience across Secondary, JC and early university mathematics, I combine diagnostic questioning, original custom problems, and real-world applications drawn from my industry background in engineering, manufacturing, finance and data analytics — to build confident, independent problem-solvers.

  • Teach to fish — build understanding that transfers to new and unfamiliar questions
  • Diagnose first — find the exact gap through targeted questions, then address it in real time
  • Custom problems — original questions designed for your specific misconceptions
  • Real-world links — connect maths to engineering, data, finance and everyday decisions

Who I Work Best With

  • Students who can follow examples but freeze when the question changes
  • Students who want to know the why behind a method, not just memorise steps
  • Students who need patient explanation and confidence rebuilding
  • Students preparing for O Level E Maths, A Maths, JC H1 or H2 Mathematics
  • Students who are both curious and mathematically advanced — interested in how mathematics connects to real life, university, and future careers
  • Adult learners returning to university-level mathematics or related subjects such as supply chain management, statistics, or engineering mathematics

Experience

2003–Present Private Mathematics Tutor & Lifelong Mentor

Started tutoring during university years; 1-to-1 and small-group tuition for Secondary, JC, Polytechnic & University Mathematics — flagship focus on JC H2 Mathematics.

2019 Guest Lecturer

Nanyang Technological University (NTU)

2018 – 2020 Tutor — Kovan Learning Centre

Secondary & JC Mathematics

2017 Tutor — AGrader Learning Centre

Secondary & JC Mathematics

2015–Present Industry Statistician & OR Expert

Global MNCs · Supply Chain · Manufacturing · Distribution · Automation · Simulation · Data Analytics · AI

2014–2015 Industry Expert · Big Data Analytics

Applied Mathematics & Analytics · Global Big Data Analytics Company

2012–2014 Industry Statistician & OR Expert

Global MNCs · Supply Chain · Manufacturing · Distribution · Optimisation · Simulation · Data Analytics · EJOR Published Research

2008 · 3 months Mathematics Teacher

Elementary School · Taitung Province, Taiwan

Background

Credentials & Qualifications

A strong academic foundation that underpins every lesson

Lester — Private Mathematics Tutor

Lester

Private Mathematics Tutor · Singapore

20+ Years Experience NUS · Georgia Tech AME Member ACLP Certified Lean Six Sigma Black Belt

Academic Qualifications

Master of Science — Industrial Engineering Georgia Institute of Technology · GPA 3.8 / 4.0
Master of Science — Logistics & Supply Chain Management National University of Singapore · CAP 4.9 / 5.0
Bachelor of Engineering — First Class Honours Industrial & Systems Engineering + Financial Mathematics · NUS & Technische Universiteit Eindhoven · CAP 4.8 / 5.0
Raffles Institution & Raffles Junior College A in JC Mathematics · A1 in O Level E Maths · A1 in O Level A Maths
Formal Education Across Three Regions

I had the privilege of formal education across three regions — each with a distinct teaching philosophy. I draw on all three to adapt my approach to each learner's needs.

🌏 Asia · Singapore (NUS) Structured and top-down — carefully organised notes, clear knowledge hierarchies, and focused delivery.
🌍 Europe · Netherlands (TU Eindhoven) Bottom-up and discussion-driven — students arrive prepared; learning is facilitated through dialogue and peer reasoning.
🌎 North America · USA (Georgia Tech) A blend of both — rigorous content delivery combined with collaborative problem-solving and strong student initiative.

Professional Certifications

Association of Mathematics Educators (AME) Member — Singapore professional body for mathematics educators
Advanced Certificate in Learning & Performance (ACLP) Formal adult education & instructional design qualification
Lean Six Sigma Black Belt Data and process-driven problem solving using advanced mathematics and statistics

Industry Experience

Industry Statistician Applied statistics, data analytics, and Lean Six Sigma concepts across multiple high-impact industry projects for global MNCs — spanning manufacturing, supply chain, engineering systems, and operations
Operations Research Expert & Trainer Simulation, optimisation, modelling, and decision science — delivered as both practitioner and trainer for global MNCs. Published research in a top-tier peer-reviewed international journal.
Published Research · EJOR (2014) Eng, S.W.L., Chew, E.P. & Lee, L.H. (2014). "Impacts of supplier knowledge sharing competences and production capacities on radical innovative product sourcing." European Journal of Operational Research, Elsevier, 232(1), 41–51.

Languages

🇬🇧 English 🇨🇳 Mandarin
Download Full Resume (PDF)
Selected Student Outcomes

Results That Speak

Significant grade improvements — and a genuine shift in confidence and mathematical thinking

E A

JC H2 Mathematics
A-Level examinations

U B

JC H2 Mathematics
A-Level examinations

4 → 21
out of 25

Score on a single topic after just 3 targeted lessons

Secondary O Level Mathematics

Students have achieved significant improvements, including A grades, through targeted concept rebuilding and consistent practice

Level & Subject Result How It Happened
JC H2 Mathematics E → A Conceptual rebuilding + exam transfer — calculus and statistics rebuilt from first principles, with custom questions targeting exact gaps
JC H2 Mathematics U → B Foundation diagnosis + targeted practice — secondary-level algebraic and calculus gaps closed before rebuilding A-Level content over two full terms
Secondary Mathematics 4 → 21 / 25 Focused weak-area correction — single topic diagnosed and rebuilt in just 3 targeted lessons

Results vary by student effort, starting point, consistency, and timeline.

Student Voices

What My Students Say

"

He creates his own questions tailored to my learning — something I've never experienced with any other tutor. Every session feels designed specifically for me.

Y
JC Student from YIJC H2 Mathematics
"

I appreciate how after teaching content, he gives real-life examples on the spot to test my understanding. I really enjoy it — I finally understand why we learn this, not just how.

T
JC Student from TMJC H2 Mathematics
"

Very approachable and encouraging. I do not feel the usual pressure I get with teachers. He is patient with my questions and explains things clearly until I actually understand.

G
Secondary School Student from St Gabriel Secondary School E Math
"

You teach really well. You are very approachable and encouraging. I learned a lot from the way you explain and solve problems — it really changed how I approach maths.

C
Secondary School Student from CHIJ St Nicholas Girls' School Additional Mathematics
The Method

The Radical Simplexity Method

A structured, scaffolded teaching process — building from foundations to independent mathematical thinking

Scaffolded learning: Every lesson moves from shallow to deep — piece by piece, building each new idea on what came before. No step is skipped. No concept is rushed. The goal is always genuine understanding, not surface coverage.

1
Foundation

Diagnose the Gap

I begin every engagement with targeted diagnostic questions — not to test, but to locate. Where exactly does the understanding break down? A student who can solve a standard question may still have a hidden conceptual gap that causes them to freeze on unfamiliar problems. We find that gap first.

2
Concept

Rebuild the Concept

I explain the why behind the method — using diagrams, analogies, and intuitive explanations before introducing the formal approach. We scaffold from the simplest case upward: start with what the student already knows, add one new layer at a time, and confirm understanding before moving on. Nothing is skipped.

3
Application

Apply to Exam Questions

Students practise on standard questions first — to confirm the concept is solid — then on unfamiliar, multi-step problems that require transferring the idea to new contexts. I write custom questions targeted at the specific gap we identified in Step 1. Every question has a purpose.

4
Extension

Connect to the Real World

Where meaningful, I show how the mathematical concept appears in the real world — drawn from my background as an industry statistician and operations research expert in engineering, manufacturing, supply chain, and finance. This is not decoration. It deepens understanding by showing why the structure exists.

5
Mastery

Build Independence

The goal is not dependence on a tutor. The goal is a student who can think through a problem they have never seen before — confidently and systematically. We work towards this from the very first session. When a student no longer needs me, that is the best outcome.

What I Teach

From Exam Confidence to Independent Thinking

Structured tuition that builds genuine mathematical ability — from O Level foundations to A Level mastery

01

Exam Confidence

For students who need stronger grades, clearer concepts, and structured exam practice. We fix the gaps and build the technique.

02

Mathematical Thinking

For students who want to handle unfamiliar questions, connect mathematical ideas, and think independently — not just follow a template.

03

Beyond School

For ambitious students curious about how mathematics connects to engineering, analytics, AI, finance, and real-world problem-solving.

1-to-1 Sessions Small Group (2–8 students) Online & In-Person
2nd Most Requested
Secondary School

Secondary School Mathematics

  • Elementary Mathematics
  • Additional Mathematics
  • Algebra, Geometry & Trigonometry
  • Calculus fundamentals
  • O Level / G3 examination prep
Students have achieved significant improvements, including A grades

Many secondary school students continue with me through to JC level.

Most Requested
Junior College

H1 & H2 Mathematics

  • H2 Mathematics (full syllabus 9758)
  • H1 Mathematics
  • Calculus & Differentiation
  • Statistics & Probability
  • Vectors & Complex Numbers
Significant grade improvements including E→A & U→B
Advanced Students & Adult Learners
Poly, University & Continuing Education

Poly & University Level Mathematics & Related Topics

For former students, advanced learners, and adult learners returning to study. Lifelong learning is always welcome.

  • Calculus & Analysis
  • Linear Algebra
  • Statistics & Probability
  • Engineering Mathematics
  • Supply Chain Management
  • Optimisation, Operations Research & Simulation
Backed by Master's-level and research-grade applied mathematics
Get in Touch

Build Real Mathematical Confidence

Share your level, current challenges, and target exam — I'll suggest the most suitable next step.

WhatsApp

Fastest way to reach me. Drop a message and I'll respond promptly.

+65 8758 8329

Instagram

Follow for maths tips, problem walkthroughs and student insights.

@radicalsimplexitymath

Singapore & Worldwide — Teaching in-person across Singapore and online around the world

Send an Enquiry

FAQ

Frequently Asked Questions

Everything parents and students commonly ask before getting started

Both. I teach in-person across Singapore and online around the world. Many students combine both depending on their schedule and location.
1-to-1 sessions for fully personalised learning, or small groups of 2–8 students. Small groups are kept intentionally small so every student receives focused attention.
Yes. I create custom questions on the fly — tailored to each student's specific misconception in real time, not prepared in advance. These are written during the session itself, designed precisely for what that student needs at that moment. Beyond the session, depending on how it went, I will also proactively go back to source or create dedicated practice questions when I feel a student needs more work on a particular concept. You can expect proactiveness.
Through diagnostic questioning at the start of each engagement. I ask targeted questions to locate the exact conceptual gap — not just the symptom. A student may be able to solve standard questions but still have a hidden gap that causes them to freeze on unfamiliar problems.
Both, in the right order. Conceptual understanding first, then exam application. Without genuine understanding, exam technique has a ceiling. Once the concept is solid, exam technique follows naturally and transfers to unfamiliar questions.
Yes. Some of my strongest results — including E→A and U→B at A-Level — began with students who had significant foundational gaps and very low confidence. This includes JC students who did not take Additional Mathematics at secondary level — a gap that creates a real disadvantage in H2 Mathematics. Having taught A Math at secondary level myself, I can rebuild that foundation in parallel with the JC syllabus. Patient, systematic rebuilding works.
Absolutely. High-performing students can take an accelerated path — exploring mathematical extensions beyond the syllabus that connect directly to university study, future careers, and real-world problem-solving. I aim to serve not just as a tutor, but as a lifelong mentor: building the mathematical curiosity and rigour that stays with students long after the exam is done.
The word Radical in Radical Simplexity is intentional. What makes my approach genuinely rare is that I bring together three domains that most educators have at most one of — and many have none: Teaching expertise (ACLP-certified, AME member, formal teaching experience in Taiwan, and 20+ years of 1-to-1 and group tutoring); Published academic research (peer-reviewed in a top-tier international journal — EJOR, 2014); and Deep industry experience applying mathematics across global MNCs in supply chain, manufacturing, analytics, and AI. Most tutors teach. Some have research backgrounds. Very few have all three. Sessions are fully personalised, built on custom questions written on the fly, and grounded in a mentorship mindset — not just getting you through an exam, but building the thinking that lasts.
Most students notice a shift in clarity and confidence within a few sessions. Measurable grade improvements typically come over one to two terms of consistent work, depending on starting point and effort. Honesty matters more to me than false promises.
Eventual Vision

Math Beyond School

The long-term vision of Radical Simplexity extends beyond the classroom

Mathematics is not just an exam subject. It is a thinking tool — for engineering, analytics, finance, AI, and everyday decisions. The future of Radical Simplexity is to make that connection visible for more students, professionals, and curious minds.

Real World Applications

See how Secondary and JC topics connect to engineering, finance, data science, and everyday decisions — with examples drawn directly from 20+ years of industry experience.

Explore Real World Maths

Math Beyond School Workshops

Short workshops connecting Secondary and JC mathematics to real-world problems in engineering, data science, AI, and finance. For students who are ahead — or just curious.

Coming Soon

Young Professional Thinking

For university students and early-career professionals who want applied statistical thinking, supply chain analytics, modelling, and mathematical problem-solving skills.

Coming Soon

Industrial Mathematics Bridge

Applied workshops in simulation, optimisation, supply chain management, manufacturing systems, and decision science — drawn from 20+ years of industry expertise.

Coming Soon

Follow along as this vision grows.

@radicalsimplexitymath