If you are reading this with three months left for your boards and a half-finished syllabus, take a breath. Almost every Class 12 student has been exactly where you are right now. We have all had that evening when the date sheet comes out and suddenly the year feels very short.
The good news is that 80% in CBSE Class 12 PCM is not a topper-only target. It is a target for any student who is willing to stay regular for about 90 days. Here is how students who have been through it usually do it.
First, stop carrying the regret
Most of us waste the first week of this phase feeling guilty. “I should have started in April.” “I wasted the whole summer.” That guilt eats time and gives nothing back.
The syllabus is still the same Class 12 board syllabus. It is not impossible, and it is not bigger than it was yesterday. What has changed is that we now have fewer days, so each day has to count. Forget what is behind you and start from today.
A teacher’s line that stays with many students is: “1% planning, 99% execution.” A perfect timetable on paper is useless if we never sit down and follow it. A simple plan that we actually follow beats a beautiful plan that we abandon in four days.
What 80% actually needs
Physics, Chemistry and Maths are each marked out of 100, with about 70 marks for theory and 30 for practicals and internals. Practicals are the easiest marks in the whole exam. A student who gets 26-28 out of 30 only needs about 52-54 out of 70 in theory to cross 80 in that subject.
So the real aim in the theory paper is around 75-77%. That is a much calmer number than “80%”. It also tells us something important: we should never ignore practical files, records and viva, because those marks are already half the battle.
Make NCERT the base of everything
Every topper and every teacher says the same thing, and there is a reason. NCERT is the foundation of the board exam, and most students who struggle are not struggling because the questions are too hard. They are struggling because they never properly finished the NCERT.
Here is how to use it well:
- Read the NCERT line by line, word by word. Do not skim. Read it at least twice.
- Highlight the new terms, definitions, exceptions and reactions with coloured pens. Colourful pages are surprisingly easy to recall during revision.
- If your teacher follows a reference book, add the extra theory in the margins, but only after the NCERT is clear.
- Solve every in-text question, every back-exercise question and the solved examples. For Maths, the NCERT examples and exercises are the heart of the preparation.
- Try the exemplar questions after that, especially in Physics and Chemistry, since they train us to handle conceptual questions.
A simple rule many students swear by: do not touch a reference book until the NCERT is under control. If the NCERT language feels too heavy, use a reference book only to understand that one topic, then come back.
Build your own formula book and short notes
Nobody remembers formulas by looking at them once. A small handbook or a few folded sheets for each subject works wonders:
- Physics: formulas, units, dimensions, constants and important graphs
- Chemistry: name reactions, conversions, exceptions, trends and important tables
- Maths: integration and differentiation formulas, trigonometric identities, matrix and vector rules
Keep it short and keep it in our own handwriting. Writing it ourselves is already half of the revision. Read it every morning and every night. If we cannot solve numericals without opening the book, the formula has not settled in our head yet.
Subject by subject
Physics
- Focus on Electrostatics, Current Electricity, Magnetism, EMI, Optics and Modern Physics, since they carry a large share of marks.
- Write every derivation twice.
- Practise a few numericals daily so the formula book stops being a crutch.
- Draw every diagram neatly and label it fully.
- Solve the VVIP questions and PYQs chapter by chapter.
| Group | Chapter | Marks (group) | Difficulty | Tip |
|---|---|---|---|---|
| 1 | Electric Charges and Fields | 16 | Hard | Learn Gauss’s law and its derivations |
| 1 | Electrostatic Potential and Capacitance | 16 | Hard | Practise capacitor numericals |
| 1 | Current Electricity | 16 | Medium | Same numerical patterns repeat every year |
| 2 | Moving Charges and Magnetism | 17 | Hard | Learn the right-hand rules, then the formulas |
| 2 | Magnetism and Matter | 17 | Easy | Mostly theory, short answers |
| 2 | Electromagnetic Induction | 17 | Medium | Understand Lenz’s law first |
| 2 | Alternating Current | 17 | Medium | Learn the phasor diagrams and formulas |
| 3 | Electromagnetic Waves | 18 | Easy | Small chapter, mostly facts and the spectrum |
| 3 | Ray Optics and Optical Instruments | 18 | Medium | Practise ray diagrams neatly |
| 3 | Wave Optics | 18 | Medium | Learn the derivations (Young’s double slit) |
| 4 | Dual Nature of Radiation and Matter | 12 | Easy | Short formulas, simple numericals |
| 4 | Atoms | 12 | Easy | Learn the Bohr model formulas |
| 4 | Nuclei | 12 | Easy | Binding energy and decay, formula-based |
| 5 | Semiconductor Electronics | 7 | Easy | Diagrams and logic gates, quick marks |
Chemistry
- Organic: Many students dread it, but with theory plus NCERT questions, five organic chapters can be covered in about five days of focused work. Keep a separate notebook for name reactions and conversions and revise it daily.
- Inorganic: Read the NCERT line by line. Many direct questions come from there.
- Physical: Practise numericals from Solutions, Electrochemistry and Chemical Kinetics regularly.
| Chapter | Marks | Difficulty | Tip |
|---|---|---|---|
| Solutions | 7 | Medium | Numerical practice is enough |
| Electrochemistry | 9 | Medium | Biggest chapter, practise numericals daily |
| Chemical Kinetics | 7 | Medium | Learn the formulas and graphs |
| d- and f-Block Elements | 7 | Easy | NCERT theory, trends and reactions |
| Coordination Compounds | 7 | Easy | Learn the naming rules once |
| Haloalkanes and Haloarenes | 6 | Medium | Learn reactions and mechanisms |
| Alcohols, Phenols and Ethers | 6 | Medium | Keep a name-reaction notebook |
| Aldehydes, Ketones and Carboxylic Acids | 8 | Hard | Many reactions, revise daily |
| Amines | 6 | Medium | Learn conversions and tests |
| Biomolecules | 7 | Easy | Pure NCERT theory, read twice |
Maths
- Solve the full NCERT first, examples and exercises.
- Then move on to the most important questions and PYQs.
- Practise Calculus a lot, since it carries heavy marks.
- Write steps clearly. Even with a small calculation slip, correct steps still earn marks.
| Chapter | Marks (unit) | Difficulty | Tip |
|---|---|---|---|
| Relations and Functions | 8 | Medium | Learn the types of relations and functions |
| Inverse Trigonometric Functions | 8 | Easy | Memorise the principal value table |
| Matrices | 10 | Easy | Rule-based, practise until automatic |
| Determinants | 10 | Easy | Formula-based, quick marks |
| Continuity and Differentiability | 35 | Medium | Practise every derivative rule |
| Applications of Derivatives | 35 | Hard | Practise maxima-minima word problems |
| Integrals | 35 | Hard | Daily practice, learn the formulas |
| Applications of Integrals | 35 | Easy | Area under curves, simple once you draw the graph |
| Differential Equations | 35 | Medium | Learn the 3-4 standard methods |
| Vector Algebra | 14 | Easy | Formula-based |
| Three Dimensional Geometry | 14 | Medium | Keep a one-page formula sheet |
| Linear Programming | 5 | Easy | Easiest 5 marks, learn it in 2 days |
| Probability | 8 | Medium | Solve all NCERT and PYQ Bayes’ theorem examples |
English
Do not leave it for the last week. Revise the writing formats (notice, letter, report, article), go through the literature chapters and practise writing within the word limit.
Practise derivations and diagrams like they are free marks
This is one of the most underrated tips. Derivations in Physics carry 4-5 marks, and they come up again and again. Every derivation should be written out at least twice on paper, not just read. The first time we may miss a step. By the second time, it flows.
The same goes for diagrams. Ray diagrams, circuit diagrams, apparatus drawings, organic mechanisms: practise each one neatly until we can draw it quickly in the exam without thinking. Examiners give marks for labelled, clean diagrams, and it is the quickest way to pick up marks without extra studying.
Previous year questions are your brahmastra
Once the NCERT is done, previous year questions (PYQs) are where the real learning for the exam begins. A student can read a chapter and feel confident, then get stuck on a PYQ and realise the chapter was not as clear as it seemed.
NCERT is the core of the preparation, and PYQs polish the rest. They show us how CBSE frames questions, which topics repeat, how marks are distributed and what kind of conceptual twists to expect.
A method that works well:
- Finish the NCERT chapter first.
- Buy a chapter-wise PYQ book for each subject. Common choices are MTG, Arihant and Oswaal. Prices vary by year, so check before you buy.
- For the first round, read the question and study the solution. Do not feel bad about looking at the answer at this stage. We are learning the pattern.
- In the second round, attempt the same questions in a separate copy without looking.
- Later, solve full papers of the last 10 years in a timed setting, once the syllabus is complete. Oswaal-type full solved paper books are handy for this stage.
Students who go through the last 10 years of papers say the same thing: confidence goes up, and so do marks. The paper stops feeling like a mystery.
Choose one book for theory and a different one for questions
This is a lesser-known tip, but a useful one. Keep theory and questions separate. Use one source to understand a topic and a different one to practise it.
Some students find that all-in-one books mix theory and questions topic by topic, so one chapter ends up taking too long and leaves them tired. Experiences differ, and plenty of students do fine with them. The point is not to blame a particular book. The point is that, in the last three months, we cannot afford to spend energy on a book that exhausts us. Pick resources that keep us moving, and stop switching.
Also, avoid buying five new books because someone online recommended them. One good NCERT-based source for theory, one for questions and one for PYQs is plenty.
Set up a daily slot system
We all have enough hours in a day. The trick is to use them without burning out. Make fixed time slots for the three main subjects, so every day has Physics, Chemistry and Maths in it. Take short breaks between slots, and do not let a break stretch into an hour of scrolling.
A sample day could look like this:
- Morning slot: Maths or Physics numericals while the mind is fresh
- Afternoon slot: Chemistry (organic one day, inorganic or physical the next)
- Evening slot: PYQs or revision of the day’s topics
- Night slot: formula book, short notes, then a clean 7 hours of sleep
Adjust it to your school or coaching timings. What matters is that the three subjects meet us every single day.
Write answers the way examiners like them
Knowing the answer is only half the job. How we present it decides the marks.
- Write theory answers in points. They are easier for the examiner to read and mark.
- Underline key words, formulas and important lines with a pencil.
- Keep the handwriting neat and the margins clean.
- Show all steps in numericals and write the unit in the final answer.
- Number every question correctly.
An examiner who has to check hundreds of copies prefers a clear, organised answer, and it often reflects in the marks.
Don’t let doubts pile up
Keep a small doubt copy. Whenever we cannot understand something, we write it down and clear it quickly with a teacher or a friend. If a topic is new or unclear, free video lectures on YouTube or Unacademy can explain it in a way that clicks. Unsolved doubts snowball, and a small confusion in the first month can become a big gap in the last month.
Teachers are the best guides for the board exam, since they know the paper pattern and how answers are marked. Note down what they say, especially about important questions, and follow their advice. At the same time, if something is unclear, always ask. A good teacher welcomes a question.
A 3-month roadmap in short
Month 1: Complete and understand. Finish the pending syllabus, read the NCERT line by line, and make formula books and short notes as we go.
Month 2: Practise. Solve NCERT questions, exemplar questions and chapter-wise PYQs. Practise derivations and diagrams.
Month 3: Revise and test. Solve full papers of the last 10 years under timed conditions, revise from notes and keep a mistake list. Sleep well.
Mistakes to avoid
- Starting too many new books in the last three months
- Skipping practical files and internals
- Skipping a chapter because it looks difficult
- Comparing ourselves with others on social media
- Reading the solution but never attempting the question
- Studying all night before the exam
Final words
Scoring 80% in the CBSE Class 12 board exam is not about studying 14 hours a day or being a genius. It is about finishing the NCERT properly, learning from the PYQs, writing neat answers and staying regular when it gets boring.
Our batch will sit for the exam in a few months, and what we do in the next 90 days will matter far more than what we did in the last 9 months. So close this tab, open the NCERT and start today.
All the best. You’ve got this.
