The Central Board of Secondary Education (CBSE) is all set to conduct the Class 10 Science Board Examination on February 25, 2026. Students across the country have now entered the final phase of their preparation, focusing on quick revisions, practising sample papers, and fine-tuning their exam strategy to maximise scores.
While most candidates focus heavily on revising concepts, experts say many students lose 10–20 marks every year, not because they lack knowledge, but because of avoidable presentation and step-related mistakes.
From omitting formulas in Physics numericals to failing to balance equations in Chemistry, minor mistakes can lead to significant mark deductions under CBSE’s step-wise marking scheme.
As the board continues to emphasise competency-based evaluation in 2026, understanding how answers are assessed has become just as important as mastering the syllabus.
CBSE CLASS 12 SCIENCE EXAM 2026: PAPER PATTERN
The maximum mark for the examination is 80, and the total time allowed to complete the paper is 3 hours.
This question paper consists of a total of 39 questions divided into three sections: Section A (Biology), Section B (Chemistry), and Section C (Physics). All questions are compulsory.
However, internal choices are provided in selected questions, and students are required to attempt only one option from the alternatives given in each such question.
Candidates are advised to read the instructions carefully before attempting the paper and manage their time effectively across all three sections.
WHY DO STUDENTS LOSE MARKS IN NUMERICALS DESPITE KNOWING THE ANSWER?
A significant number of students lose marks in numericals, not because they lack understanding, but because they fail to present their solutions systematically. Teachers and examiners consistently observe that the maximum deductions occur in Physics chapters such as Light and Electricity and in Chemistry topics like Chemical Reactions and the Mole Concept, primarily due to avoidable “step errors.
Under the CBSE marking scheme, marks are distributed across each stage of the solution, not reserved solely for the final answer. This step-wise evaluation means that students are rewarded for:
- Writing the correct formula before solving
- Substituting the given values accurately
- Performing correct calculations
- Converting units properly
- Presenting the solution in a logical sequence
Importantly, even if the final answer turns out to be incorrect due to a calculation mistake, students can still earn partial marks if the method and steps are correct.
However, many students make the mistake of writing only the final answer without showing the formula or calculations. In such cases, examiners have no basis to award step marks, which often results in unnecessary loss of valuable points, even when the numerical answer is correct.
WHAT ARE THE MOST COMMON PHYSICS MISTAKES?
Physics numericals are among the highest-scoring sections of the paper, but only when students follow a clear, step-by-step method. A large number of marks are lost not due to conceptual misunderstanding, but because of careless presentation errors.
“Never skip writing the formula, even if the calculation looks simple. The formula carries marks, and it also shows the examiner that you understand the concept, not just the numbers. Always box your final answer and double-check the unit before moving to the next question,” said the Class 10 Science teacher of a Delhi school.
Students should solve every numerical using the structured approach of clearly writing what is given, stating what is to find, mentioning the correct formula, showing proper substitution of values, and finally presenting the final answer with the correct unit.
This systematic approach ensures that each stage of the solution is visible to the examiner, increasing the chances of securing full marks, even if a minor calculation error occurs at the end.
WHERE DO STUDENTS SLIP UP IN CHEMISTRY?
In Chemistry, presentation plays a decisive role. Frequent mistakes include:
- Forgetting to balance chemical equations
- Skipping states of substances (s, l, g, aq)
- Not showing the mole calculation steps
- Writing answers without proper units
Even a simple unbalanced equation can result in loss of step marks, especially in 3–5 mark questions.
IMPORTANCE OF DIAGRAMS AND PRESENTATION
In the Biology section, students often lose easily and score poorly due to presentation-related mistakes rather than a lack of knowledge. Common errors include failing to draw properly labelled diagrams, sketching unclear or untidy figures, and not using a pencil for diagrams as required.
Examiners place significant importance on neatness, correct labelling, and clarity of diagrams. A well-drawn, accurately labelled figure can fetch full marks, while a messy or incomplete one may lead to unnecessary deductions.
Therefore, maintaining precision and presentation quality in diagrams remains a crucial scoring factor in the Biology paper.
WHY DOES STEP-WISE MARKING MATTER MORE IN 2026?
The 2026 board exams continue to follow a competency-based assessment pattern. Examiners are instructed to evaluate:
- Logical flow
- Conceptual clarity
- Application of formulas
- Step-by-step reasoning
This means skipping steps, even during mental calculations, can lead to deductions. The Board prioritises the process, not just the final digit.
WHAT TIME MANAGEMENT MISTAKES SHOULD STUDENTS AVOID?
Poor time management often affects performance in the final hour. Experts advise students to avoid:
- Spending too long on one difficult numerical
- Leaving 5-mark questions for the end
- Not keeping time for revision
- Writing lengthy answers to short questions
Students are encouraged to divide the three-hour paper strategically and reserve at least 15–20 minutes for review.
SMART WRITING CAN MAKE A DIFFERENCE
As the February 25 Science Board Exam approaches, students are reminded that scoring well is not only about how much they study, but also about how effectively they present their answers in the examination hall.
With step-wise marking playing a crucial role in the 2026 evaluation pattern, clarity, structure, and disciplined time management could mean the difference between an average score and a distinction.
For thousands of candidates, avoiding these small but costly mistakes may be the smartest revision strategy in the final hours before the exam.
