Ban the word 'obvious'
Nothing in mathematics is obvious to the person it isn't obvious to. The single vocabulary change that transformed my classroom.
Read note →
§ 01 · Axioms
— V. Shastri, ∀ students ∃ a way in
Q.E.D. is a feeling.
I was the school 'maths person', which taught me nothing about teaching. What taught me was my sister — bright, articulate, and convinced by one bad teacher that numbers hated her. Rebuilding her confidence over a summer of kitchen-table fractions was harder than my M.Sc., and infinitely more instructive. I've been running that summer at scale for eighteen years.
My classroom runs on productive struggle: problems calibrated to the edge of each student's ability, a strict no-early-rescue policy, and a wall of 'beautiful mistakes' — wrong answers that taught the whole class something. Results follow: 312 JEE qualifiers, a 97% board average at peak, and a steady stream of self-declared 'not maths people' who now do engineering degrees out of spite.
If your school wants a mathematics department where anxiety is treated as a curriculum defect rather than a student defect — and where the board results prove the theorem — state your terms. I respond to well-posed problems.
Classroom axioms
Assumed true · never violatedAX.1Every wrong answer contains information.
AX.2Struggle is the lesson, not the obstacle.
AX.3No one copies the working. Ever.
AX.4'Obvious' is a banned word.
AX.5The board is never erased mid-proof.
§ 02 · Theorems held
Proven results
Eighteen years from number lines to calculus — every claim comes with a proof.
πSignature
Algebra & calculus
Gr 11–12 core, taught as one connected storyπSpecialist
Geometry & trigonometry
proof-first, compass-and-straightedge to coordinatesπ312 qualifiers
JEE / competitive problem craft
problem sets, error autopsies, timing strategyπThe specialty
Maths-anxiety repair
diagnostic interviews, floorboard repair, confidence arcsπ4 INMO
Olympiad mentoring
PRMO → INMO pipeline, proof-writing craftπSpecialist
Statistics & probability
data-first, real datasets, healthy scepticism
§ 03 · Proof strategy
Struggle is the syllabus
Somewhere in Grade 5, a child gets one bad week of fractions and files themselves under 'not a maths person' for life. My whole career is prosecuting that filing error. Give me the student, one problem calibrated exactly to the edge of their ability, and silence. The moment it cracks — that Q.E.D. feeling — is chemically addictive. After that, I mostly just supply harder problems.
- DiagnoseNot 'weak in maths' — weak in what, exactly? A ten-minute interview finds the precise floorboard that broke, usually years ago.
- RepairWe go back to that floorboard without shame. Fractions at fourteen is not remedial; it's structural engineering.
- StruggleProblems pitched at the edge of ability, and I do not rescue early. Productive struggle is the entire syllabus.
- ProveBoard-exam craft, JEE problem sets, and writing solutions others can read — because a proof is an act of communication.
§ 04 · By induction
Eighteen years, n → n + 1
2015 — PRESENT
Head of Mathematics (PGT)
DAV Public School, Pune
Lead an eight-teacher department. Built the 'diagnostic-first' remediation system now used school-wide, the JEE stream (312 qualifiers), and the Beautiful Mistakes wall that three visiting principals have photographed. 97% board average at peak.
2010 — 2015
Mathematics Teacher (TGT → PGT)
Symbiosis School, Pune
Grades 6–12; developed the edge-of-ability problem bank — 2,400 problems tagged by exact prerequisite — that I still maintain and will bring with me.
2007 — 2010
Junior Mathematics Teacher
City International School, Pune
Middle-school maths; learned that the phrase 'this is easy' has destroyed more mathematical careers than any exam ever set.
§ 05 · Lemmas
Education
2005 — 2007
CPI 9.1 · number theory specialisation
M.Sc. Mathematics
IIT BombayCPI 9.1 · number theory specialisation
2007 — 2008
Distinction
B.Ed. (Mathematics)
SNDT University, PuneDistinction
2002 — 2005
First class · university rank 1
B.Sc. Mathematics
Fergusson College, PuneFirst class · university rank 1
§ 06 · Definitions
Certifications
∎
Olympiad resource person (mathematics)HBCSE-TIFR programme · 2019
∎
IB DP Mathematics AA (Cat 1)IB workshop, Mumbai · 2022
∎
Cognitively Guided Instruction trainingCertified · 2020
∎
CBSE competency-based assessmentCoE training · 2023
§ 07 · Corollaries
Results that follow
∴
Best Mathematics Teacher — MaharashtraState sahodaya teaching awards
2024∴
312 JEE qualifiers mentoredMathematics stream, DAV Pune
2015–∴
4 INMO qualifiersSchool's first in its history
2019–∴
Published — 'The Floorboard Method'Teacher Plus, on diagnosing maths anxiety
2022
§ 08 · Marginalia
JUN 2026 FEB 2026 OCT 2025
Notes in the margin
Fractions at fourteen
The case for shameless remediation — why going back four years in front of a teenager works, if you frame it as engineering.
Read note →In praise of the beautiful mistake
How a wall of celebrated wrong answers rewired my class's relationship with error — and quietly raised the board average.
Read note →
§ 09 · Peer review
Independently verified
REVIEW 1 · ACCEPTED, NO REVISIONS
My daughter cried over maths for three years. Mr. Shastri found the exact gap — decimals, Grade 5 — fixed it in a month, and she just chose engineering.
Anaya's fatherPARENT · GR 12REVIEW 1 · ACCEPTED, NO REVISIONS
His remediation system halved our failure rate in two years. Other departments now copy the diagnostic-interview model.
PrincipalDAV PUBLIC SCHOOL, PUNEREVIEW 1 · ACCEPTED, NO REVISIONS
I told him I wasn't a maths person. He said 'interesting hypothesis, let's test it'. I'm at IIT Delhi now. Hypothesis rejected.
KabirALUMNUS · IIT DELHI
§ 10 · For schools
Statement of the theorem
∑ SESSION 2027–28 · ONE DEMO CLASS: GIVE ME YOUR 'WORST' MATHS BATCH AND ONE PERIOD
Current employerDAV Public School, Pune
Current roleHead of Mathematics (PGT)
Open toPGT Mathematics · HOD · JEE/olympiad programme lead
Expected salary₹14–18 LPA
Notice period90 days
Willing to relocateYes — Pune, Mumbai, Bengaluru · CBSE / ICSE / IB
Principal, DAV Public SchoolCURRENT EMPLOYER · SHARED ON REQUEST
HOD Science & Maths, Symbiosis School2010–15 · SHARED ON REQUEST
§ 11 · Correspondence
Solve for x
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