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Class 10 science is one paper but three subjects, and it is tempting to revise whichever you like best. A better plan starts from what CBSE has published for the 2026-27 session: the syllabus with marks per unit, a sample question paper, and a marking scheme. This post turns those into a six-week revision plan.
What does the 2026-27 paper look like?
The CBSE Class X Science curriculum for 2026-27 sets a 3-hour theory paper of 80 marks, plus 20 marks of internal assessment. The theory marks are split by unit:
Unit I, Chemical Substances: Nature and Behaviour: 25 marks
Unit II, World of Living: 25 marks
Unit III, Natural Phenomena (light): 12 marks
Unit IV, Effects of Current: 13 marks
Unit V, Natural Resources: 5 marks
The same document gives the question paper design: about 50 per cent of marks test knowledge and understanding, 30 per cent application, and 20 per cent analysing, evaluating and creating. There is an internal choice in roughly a third of the paper. It also lists some topics as assessed only formatively, not in the year-end exam: Periodic Classification of Elements, the Evolution topics, and the motor, electromagnetic induction and electric generator. Its note for teachers adds Heredity to the topics not assessed in the year-end exam. Read that list before you plan.
The 2026-27 sample question paper has 39 questions in three sections: Section A is Biology, Section B is Chemistry and Section C is Physics. Its matching marking scheme shows how marks are split inside each answer.
Two board exams: what changed in 2026
CBSE introduced two board examinations for Class X from 2026. According to CBSE's press release of 18 July 2026, the main exam ran from 17 February to 11 March 2026 and the second exam from 15 to 21 May 2026. For regular students, the better of the two performances counts. Of the 5,13,955 candidates who took the second exam to improve, 3,08,095 (59.95 per cent) improved on their main-exam result.
That second chance is useful, but plan to do your best in the main exam. Check CBSE's circulars for the rules that apply to your year.
A six-week plan weighted by marks
In the CBSE curriculum, Units I and II carry 50 of the 80 theory marks, so they get the most time. Each week has five study days and one mixed-review day.
Week 1: Chemistry foundations. Chemical reactions and equations, then acids, bases and salts. Balance ten equations a day from memory.
Week 2: Chemistry continued. Metals and non-metals, then carbon and its compounds. Make a one-page sheet of reactions and naming rules, then test yourself from a blank page.
Week 3: Biology. Life processes, then control and coordination. Draw and label each process figure from memory, then check it against NCERT.
Week 4: Biology and environment. Reproduction and our environment (Unit V). The curriculum's note for teachers says Heredity will not be assessed in the year-end exam, so check with your teacher before revising it.
Week 5: Physics. Light (mirrors, lenses, the eye, refraction through a prism) and electricity with its magnetic effects. Do numericals daily, with units written at every step.
Week 6: Papers. Take the sample paper under timed conditions, mark it with the marking scheme, then take a second paper later in the week.
On each mixed-review day, answer 20 questions drawn from every unit covered so far. Mixing the units makes you pick the right idea yourself, as you must in the board paper.
Don't skip the practicals
The curriculum lists 14 experiments, from finding pH with indicator paper to tracing light through a glass slab and a prism. Practical work carries 5 marks of internal assessment, and theory questions can be built around experiments. For each experiment, write from memory: aim, what you do, what you observe, and the conclusion. Then check it against the NCERT lab manual.
Light and circuits: practise the pictures
The sample paper asks for diagrams as well as answers; one question asks for a simple labelled diagram showing how white light splits through a prism. Draw two ray diagrams a day in Week 5: one mirror and one lens, with the object at a different position each time. Before drawing, predict where the image will form and what it will look like.
If you find a ray diagram or circuit hard to picture, an interactive version can help. The Fermi Simulation Lab has interactive simulations for ideas that are easier to see than to read. Make your prediction first, then test it.
To space your revision beyond these six weeks, use this 4-week spaced revision schedule. For using past papers well, see how to use previous-year papers without memorising answers. If your family is already thinking about Class 11, read choosing a stream after Class 10.
Download the sample paper and marking scheme today, and put Week 1 in your calendar.
