How examiners give marks: one real answer, step by step
The rules CBSE examiners mark by, and one 3-mark proof split into four steps: half a mark, 1, 1 and half a mark. What the examiner may accept, and why working earns marks.
CBSE examiners give marks by the marking scheme, not by feel. The scheme splits each question into steps and fixes what each step earns. The examiner awards every step the answer reaches, by any valid method. One error should cost marks only once. So the unit of marking is the step, not the whole question.
How do examiners give marks in CBSE?
They follow a set of rules the board prints for them. The rules sit at the top of every board-exam marking scheme on CBSE's marking scheme page. The 2026 Class 10 schemes say marking "should not be done according to one's own interpretation". The scheme is to be "strictly adhered to".
The same rules push the other way too. They say: "Please do not hesitate to award full marks if the answer deserves it". If a student answers an extra question, the answer that earns more marks is kept. The other is struck out with a note.
How are marks awarded in CBSE Maths? One real answer
Take the proof that the square root of 5 is irrational. It was Question 26 of a 2026 CBSE Class 10 Maths Standard board paper, for 3 marks. TRUpreBoards' own reconstruction of that paper's scheme divides those three marks across four steps, in half-mark units. This is our reading, not the board's document, as the last section explains. The idea behind it is step marking. See how step marking splits a question's marks.
- Half a mark - for the starting assumption: suppose root 5 is a over b, with no common factor.
- One mark - for squaring to get 5b² = a², so 5 divides a.
- One mark - for putting a = 5c and showing, the same way, that 5 divides b.
- Half a mark - for the contradiction: 5 divides both a and b, which the assumption ruled out.
The board's own sample papers split marks the same way. In the 2026-27 Maths Standard sample, a 2-mark sector question gives half a mark for the radius. It gives 1 mark for the formula with the numbers in, and half a mark for the answer. What a CBSE marking scheme contains walks through it.
Why are marks split into halves?
Because 3 marks do not divide evenly over four steps. Whole marks only would force the scheme to merge two steps or drop one. Half marks let a 3-mark proof pay for the assumption, both halves of the argument and the ending.
The unit of award is the step. A question is only the container the steps arrive in.
This is also why a total says so little. Two students can each lose 3 marks on a paper. One lost them on method, the other on final answers. The mark sheet shows the same number for both.
Does the examiner have to accept your child's method?
Yes, if the method is valid. The board's 2026 rules cover answers that are new or "innovative". These may be checked for correctness and given due marks. Two questions in the Class 10 Science scheme are competency-based - they test using an idea in a new situation. For these two, examiners are told to try to understand the answer given.
Our reconstruction of that 2026 paper states three rules for its marker. Each one protects a different kind of answer.
- Any valid method earns the step. For a route the scheme does not print, the examiner awards the equivalent step marks for the equivalent stage reached.
- An error is carried forward, not charged twice. Later steps are marked on the student's own figures. This matches the board's rule that an error is penalised only once.
- In proofs, marks sit on the reasoning, not the wording. The question is whether the reasoning reached the stage the mark is for.
Read together, these rules describe an examiner looking for marks to give. One thing no rule can fix: the step was not on the page to mark.
Why does a correct final answer with no working lose marks?
Because the other steps have nothing to be matched against. Suppose a script writes only that root 5 is irrational. In the four-step split above, that reaches the last half mark at most. The two and a half marks before it are for steps that are not on the page.
It works the other way too, and that is the part worth telling a child. Set the question up correctly, slip in the last line, and the earlier steps are still earned. A wrong answer is not always zero. A right answer is not always full marks.
What do CBSE examiners look for in an answer?
The value points in the scheme, and nothing else. In practice that means a few plain things:
- Each step the scheme names. In Maths, this is often the set-up, the formula with the numbers in, and the answer with its unit.
- Each point a Science answer asks for. Where a question wants two points, each may carry its own half mark.
- The diagram, where one is asked for. In the 2026-27 Science sample marking scheme, the diagram in Question 39 carries 2 of its 5 marks.
- Your meaning, in your words. The scheme's wording is a guide. A correct point made differently should still earn the mark.
That last point is where two examiners can read the same answer differently. Our page on why two examiners can give different marks looks at how CBSE keeps that in check.
What helps the examiner mark your answer in Class 10?
- Write the step that feels too easy to write. It may be a line in the scheme, worth half a mark.
- Number each answer as the paper does. The examiner marks by question, against the scheme for that question.
- Keep an answer in one place. Marks for each part are written beside it, then totalled for the question.
- Strike out rough work with a single line. The examiner can then see which working you want marked.
For what happens to the answer book before and after it reaches the examiner, read how your answer sheet is actually checked.
What is not being claimed here?
The √5 step split is not CBSE's. It is TRUpreBoards' step-wise reconstruction of that 2026 board paper, written to show where marks sit in a question. It says on its own face that it is not the board's official marking scheme and carries no CBSE endorsement.
Its totals match the paper's: the five sections add up to 80 marks. But matching is not endorsement. Where it and the board's scheme differ, the board's version wins. The six rules above are the board's own, from its 2026 marking schemes.
No frequency is claimed either. Nothing here counts how often a mark is lost at any step, because no scripts were counted for it.
Sources
Facts last checked against these sources on 30 September 2026.
About the author
Chief Architect
An engineer (B.Tech, Computer Science) with over 20 years of preparing students for entrance exams, including as Dean at FIITJEE and Vice-President at Aakash. He is the chief architect of the TRUpreBoards evaluation engine.
Mohit Sardana on LinkedIn
