Switching Between ICSE and CBSE: Maths and Science Gaps
Switching from ICSE to CBSE in Class 9 usually means less arithmetic and fewer topics in maths, but a new style: NCERT-based questions, about half the board paper competency-based, and in 2026-27 a brand-new Class 9 book. Switching from CBSE to ICSE is the harder direction: commercial maths, logarithms, trigonometry from Class 9, geometry proofs, and three separate science papers instead of one. This guide maps the gaps class by class from the official CISCE and CBSE syllabi, and gives a six-week plan to close them.
The maths and science facts below come from CISCE's syllabus documents for the 2027 ICSE examination and CBSE's 2026-27 curriculum on cbseacademic.nic.in. For moves between CBSE and IB or IGCSE, read our separate post on moving from CBSE to IB or IGCSE.
When families switch, and the easier and harder years to do it
In Gurugram, a board change usually follows a move into the city, a change of school for distance or fit, or a decision about Classes 11 and 12. The family's reasons are their own; the academic question is the same: which topics has the child missed, and which will they see twice?
- Easier: up to the start of Class 8. There are no board papers yet, school syllabuses overlap a great deal, and a few months of steady work closes most gaps.
- Manageable: the start of Class 9. Both boards treat Classes 9 and 10 as the build-up to the board exam. CBSE treats IX and X as one composite course, so joining at the start of IX means the child begins the course with everyone else. This is where a clear gap plan pays off.
- Harder: mid-way through Class 9, or Class 10. The board-year syllabus builds on Class 9 topics the child may never have met, and internal assessment runs through the year. It can be done, but expect several months of extra work in maths and science.
Families moving between boards in Gurugram meet both systems across the city; for example, Blue Bells Model School in Sector 4 follows CBSE, while Scottish High International School in Sector 57 and The Shri Ram School's Moulsari campus in DLF Phase 3 offer ICSE, as listed on their own sites and board directories.
ICSE to CBSE: maths topics that disappear and NCERT styles to learn
An ICSE student entering CBSE Class 9 in 2026-27 will find several familiar ICSE Class IX topics missing from CBSE's Class IX chapter list. Compound interest, logarithms, trigonometry and geometric constructions do not appear among the 15 chapters of CBSE's Standard-level Class IX maths. Logarithms appear only in CBSE's optional Mathematics Advanced, and trigonometry starts in CBSE Class X.
In their place, CBSE's new Class IX book, Ganita Manjari, brings chapters an ICSE student will not have seen in that form:
- Sequences and Progressions. ICSE introduces arithmetic and geometric progressions only in Class X.
- Introduction to Euclid's Geometry: Axioms and Postulates. Short, but new in style.
- Introduction to Probability. ICSE Class IX has statistics but leaves probability to Class X.
- Introduction to Polynomials and Exploring Algebraic Identities. ICSE students know expansions and factorisation, but CBSE frames them as polynomials from Class IX.
The bigger change is style. By CBSE's own count, roughly half of its board questions now test competencies, built around a case, a source, a set of data or a real application. Its Class IX maths paper gives roughly 54% of marks to recall and understanding, 24% to application and 22% to higher-order thinking. An ICSE student used to long, computation-heavy sums often needs practice in reading a short case, picking out the maths, and answering several linked parts briefly.
Mini-example: a progression, CBSE Class IX style
Seats in a hall are arranged so that the first row has 3 seats, the second 7, the third 11, and so on. How many seats are in the 20th row, and in the first 20 rows together? The common difference is 4, so the 20th term is 3 + 19 × 4 = 79. The sum of 20 terms is 20 ÷ 2 × (3 + 79) = 10 × 82 = 820. An ICSE student would meet this in Class X; in CBSE it now comes in Class IX, wrapped in a short real-life context.
CBSE to ICSE: commercial maths, geometry with reasons, three science papers
This is the direction with more new content. In both Class IX and Class X, ICSE Mathematics is a single paper of 3 hours and 80 marks, with internal assessment adding 20; and the Class IX syllabus alone already includes:
- Commercial Mathematics: compound interest, including half-yearly compounding, growth and depreciation.
- Logarithms and indices, with the laws of logarithms used to expand expressions.
- Trigonometry: ratios, standard angles and complementary angles, a year earlier than CBSE.
- Geometry with reasons: congruency, the mid-point and equal intercept theorems, Pythagoras theorem with an area-based proof, area theorems on parallelograms and circle properties. CISCE's syllabus says proofs of these theorems are to be taught unless stated otherwise.
- Constructions with ruler and compasses only.
In Class X, ICSE adds topics with no CBSE Class X counterpart: GST, recurring deposit accounts, shares and dividends, linear inequations, ratio and proportion (including componendo and dividendo), the factor and remainder theorems, matrices, geometric progressions, loci, and reflection and the equation of a line in coordinate geometry. Some questions may also need logarithmic and trigonometric tables, which CBSE students have usually never used.
Mini-example: a recurring deposit, ICSE Class X style
A student deposits ₹1,000 a month for 12 months at 6% a year. Using CISCE's formula, interest I = P × n(n + 1) ÷ (2 × 12) × r ÷ 100 = 1,000 × (12 × 13) ÷ 24 × 6 ÷ 100 = 1,000 × 6.5 × 0.06 = ₹390. The maturity value is P × n + I = 12,000 + 390 = ₹12,390. Nothing here is hard, but a CBSE student has never seen the formula, and ICSE papers expect it to be set out step by step.
Science: one paper becomes three
In CBSE, Science is a single subject: one theory paper out of 80, and 20 marks awarded by the school. In ICSE, the three sciences are separate exams; Physics, Chemistry and Biology each have their own 2-hour paper out of 80, with practical work adding 20 more. So a CBSE student moving to ICSE goes from one science exam to three, each with its own practical record.
Content also differs. ICSE Class IX Physics has separate headings for Measurements and Experimentation and for Fluids, which CBSE's four Class IX science units do not name. ICSE Class IX Chemistry includes The Language of Chemistry, the periodic table and the gas laws. ICSE Class IX Biology covers flowering plants, diversity in living organisms, and health and hygiene. In Class X, ICSE Chemistry goes into mole concept and stoichiometry, electrolysis, metallurgy and analytical chemistry; Physics adds heat and modern physics; Biology adds population, human evolution and pollution. Several of these go beyond the topics listed in CBSE's examined Class X science content, so a CBSE student should expect new chapters, not just new questions.
A gap table by class
This table compares the official 2026-27 CBSE chapter lists with CISCE's syllabus for the 2027 ICSE examination. CISCE does not publish the Class 6–8 detail in the documents we checked, and NCERT's Class 6–8 chapter lists sit inside the books themselves, so for those classes compare the two schools' book lists directly.
| Moving into | Maths: likely gaps | Science: likely gaps |
|---|---|---|
| CBSE Class 9 (from ICSE Class 8) | Sequences and progressions, Euclid's axioms, introduction to probability, polynomial language | The new CBSE book Exploration; one combined paper and competency-based questions |
| CBSE Class 10 (from ICSE Class 9) | Areas related to circles, sequences and progressions from CBSE Class IX, NCERT-style case questions | Chemical reactions, acids, bases and salts, metals and non-metals, carbon compounds; life processes, reproduction, heredity; light and electricity in CBSE's order |
| ICSE Class 9 (from CBSE Class 8) | Compound interest, logarithms, trigonometry, constructions, theorem proofs | Three separate subjects; measurements and experimentation, fluids, the language of chemistry, gas laws |
| ICSE Class 10 (from CBSE Class 9) | All of ICSE Class IX above, plus GST, recurring deposits, shares, matrices, inequations, loci, the factor theorem, log and trig tables | Mole concept, electrolysis, metallurgy, analytical chemistry; heat and modern physics; population and human evolution; three practical records |
Two cautions. First, a gap table shows topics, not depth: the same chapter title can be taught at different levels. Second, check the new school's own scheme for Class 9; in CBSE, for example, the school runs Class IX exams on a pattern close to the Class X Board exam.
A six-week bridging plan
Start as soon as the move is certain, ideally in the break before the new session. Two or three sessions a week with a tutor, plus short daily practice, is enough for most students.
| Week | Maths | Science |
|---|---|---|
| 1 | Diagnostic test on the new board's previous-class topics; list the gaps from the table above | Same diagnostic; get the new school's books, lab record format and term syllabus |
| 2 | The largest missing topic (CBSE to ICSE: compound interest and indices; ICSE to CBSE: sequences and progressions) | CBSE to ICSE: start a separate notebook for each science; ICSE to CBSE: read the first chapters of Exploration |
| 3 | Second missing topic (logarithms or trigonometry; or probability and polynomials) | Missing practical skills: measurement and recording, or NCERT activity-style questions |
| 4 | Geometry: theorem proofs for ICSE, or Euclid and case-style questions for CBSE | Chemistry language and equations, which both boards rely on |
| 5 | Mixed practice in the new board's question style, untimed | Short answers and diagrams in the new board's style |
| 6 | One timed paper or section; review every lost mark | One timed paper per subject; set a weekly routine for the term |
After the six weeks, keep one session a week for the first term focused on the remaining gaps, and use the first school test as a check. If the test shows the same gaps, extend the plan rather than adding new material.
Mini-example: logarithms in a sentence
A CBSE student moving to ICSE Class 9 can learn the core idea quickly: log 1000 = 3 because 10³ = 1000. Then the laws follow: log 8 + log 125 = log (8 × 125) = log 1000 = 3. Starting with one clear example like this, before any rules, makes the new topic feel manageable.
How NXTutors can help
NXTutors is based in Sector 66, Gurugram, and arranges home tutoring across Gurugram and online tutoring across India. For a board switch, tell us the old board, the new board, the class and your area, for example Sector 57, DLF Phase 3 or Old Gurugram. We shortlist two or three tutors; in the demo, ask each one how they would handle the switch. You see each tutor's fee before the demo, the first class is a free demo, and switching tutor later is free.
Pages for each side of the switch:
- ICSE: ICSE maths tutors, ICSE physics tutors, ICSE chemistry tutors and ICSE biology tutors in Gurgaon.
- CBSE: CBSE maths tutors and CBSE science tutors in Gurgaon.
- The most common switching year: Class 9 maths tutors in Gurgaon.
- Moving to the city: our guide to schools and tutoring when moving to Gurgaon.
Or browse every option on our page of home tutors in Gurgaon.
Frequently asked questions
Is switching from ICSE to CBSE in Class 9 hard for maths?
Switching from ICSE to CBSE in Class 9 is usually not hard for maths, because most ICSE Class IX topics are already familiar. Some, such as compound interest, logarithms and trigonometry, are not in CBSE's Class IX list. The work is in the new chapters, sequences and progressions, Euclid's axioms and probability, and in learning CBSE's competency-based question style.
What is the main difference between ICSE and CBSE maths syllabi?
The main difference between ICSE and CBSE maths syllabi is breadth: ICSE adds commercial mathematics, logarithms, matrices, loci and more theorem proofs. ICSE's commercial maths includes compound interest, GST, recurring deposits and shares, and it starts trigonometry in Class 9. CBSE has fewer topics and puts about half its board questions in competency-based formats built around a case, source or data set.
Can a student switch from CBSE to ICSE in Class 8?
Yes, the start of Class 8 is one of the easier points to switch from CBSE to ICSE, because there is no board-pattern exam yet. School syllabuses also overlap a great deal. Use the year to learn the ICSE style: more arithmetic, proofs with reasons, and three separate sciences from Class 9. A short bridging plan in the first term is usually enough.
How is ICSE science different from CBSE science?
ICSE science differs from CBSE science mainly in structure: ICSE Physics, Chemistry and Biology are three separate exams, while CBSE Science is one. Each ICSE paper is out of 80, with 20 more marks per subject for practical work; CBSE Science is out of 80, with 20 school-awarded marks. Content differs too, for example ICSE's fluids, gas laws, electrolysis, metallurgy and modern physics.
How long does it take to bridge the gap between ICSE and CBSE?
Bridging the gap between ICSE and CBSE at the start of Class 9 takes about six weeks of focused work, with lighter follow-up through the first term. Two or three tutor sessions a week plus short daily practice is enough for most students. A switch in Class 10 takes longer, because the new board's Class 9 topics must be learned alongside the board-year syllabus.
Do ICSE students need log tables?
Yes, ICSE students may need log tables, because CISCE's syllabus says some ICSE Mathematics questions may require logarithmic and trigonometric tables. CBSE students have usually never used them. A student moving from CBSE should practise reading both tables, alongside the laws of logarithms, before the first ICSE test so that the unfamiliar format does not cost time in the paper.
Which ICSE Class 10 maths topics have no CBSE Class 10 counterpart?
ICSE Class 10 maths has several topics with no CBSE Class 10 counterpart, including GST, recurring deposit accounts, shares and dividends, matrices and loci. The list also covers linear inequations, componendo and dividendo, the factor and remainder theorems, geometric progressions, and reflection and the equation of a line. A CBSE student joining in Class 10 must also cover the ICSE Class IX topics.
