The CBSE Class 10 Science Board Exam 2026 is scheduled for February 25, 2026, which means the final revision phase has already begun. At this stage, students must focus on avoiding mistakes that reduce marks.
Your focus should be on refining presentation, strengthening weak areas, and eliminating careless mistakes. Below are the most common mistakes that cut marks and how you can avoid them before the exam.
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Not Reading the Question Carefully
Many students rush through questions and miss key instructions like:
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“State two differences”
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“Draw and label”
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“Explain with reason”
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“Name the process”
Missing such instructions leads to incomplete answers and loss of marks. Always underline keywords in the question paper before answering.
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Ignoring Units in Numericals
In Physics and Chemistry numericals, students often forget to write units, use wrong unit conversions, and skip writing formulas before substitution. CBSE awards step marking. Always follow this format:
Given → Formula → Substitution → Final Answer with Unit
Even if the final answer is slightly wrong, proper steps can save marks.
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Poor Diagram Presentation
In Biology and Physics, diagrams are drawn without labels or the labellings are messy or written inside the diagram. Neat, properly labeled diagrams can easily fetch full marks. Practice drawing important diagrams like human heart, ray diagrams, electric circuits, etc.
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Writing Too Much or Too Little
Some students write lengthy paragraphs for 2-mark questions and too little for 5-mark questions. Remember: 2 marks → 2 clear points, 3 marks → 3 structured points, and 5 marks → explanation with steps/diagram/examples. Write to the mark allocation, not beyond it.
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Weak Chemical Equations
In Chemistry, common errors include unbalanced equations, missing state symbols, incorrect valency, and forgetting reaction conditions. Balanced and correctly written chemical equations are important for full marks.
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Skipping NCERT-Based Statements
CBSE papers are based on NCERT. Students who rely only on guidebooks sometimes miss exact NCERT definitions and keywords. Revising textbook lines can prevent loss of easy theory marks.
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Poor Time Management During Exam
Students often spend too much time on one section and rush through the rest. You should give the first 15 minutes for reading the question paper carefully. Attempt known questions first and keep the last 10 minutes for revision. Time management can prevent avoidable mistakes.