BHSEC (Class XII) common mistakes
BHSEC (Class XII) · Understand the traps and how to avoid them.
In English, the candidate retells the plot of a passage instead of answering the set question (for example, summarising a story when asked to analyse the writer's tone), so the response scores for content recall but not for the skill being tested.
Under time pressure, students fall back on the safest thing they know - the story - because they have practised comprehension as reading, not as question-type recognition. They skim the question stem and latch onto a familiar word.
What to do instead
Before writing, underline the command word (describe, compare, analyse, justify) and the focus of the question, then draft a one-sentence answer that begins with that command word. Practise past-paper stems by matching each to its required response type in a two-column table for ten minutes per session.
In Dzongkha, the candidate writes the essay or letter in spoken colloquial register, mixing informal spoken forms and English loanwords into formal written Dzongkha, and misapplies the honorific register (zhe-sa) for the intended reader.
Everyday speech dominates exposure, and formal written conventions are practised less. Students also transfer English sentence structure and vocabulary when a Dzongkha term is not recalled instantly.
What to do instead
Keep a running glossary of formal written alternatives to colloquial words and of honorific verb pairs, and rewrite one short colloquial paragraph into formal register each week. Before the exam, memorise the opening and closing formulae for the letter and essay formats and check the register of the addressee first.
In Mathematics, the candidate substitutes numbers into a formula or begins algebra before establishing the condition the question requires (for example, solving for x without using the stated constraint), producing a correct-looking but irrelevant result.
Formula recall is over-practised relative to problem interpretation, and students treat every question as a template-matching exercise. Reading speed under exam pressure encourages jumping to computation.
What to do instead
Adopt a fixed three-line setup: write the given information symbolically, state what is to be found, then choose the method. Do timed drills where the only task is to write the setup for ten problems without solving them, then check the setups against the mark scheme.
In Physics, the candidate omits units, uses inconsistent units within one calculation (for example, centimetres with metres), or drops the direction of a vector quantity, so a numerically correct answer loses marks or is physically wrong.
Students treat units as decoration rather than part of the quantity, and numerical habits from earlier years persist. Vector direction is often mentally noted but not written down.
What to do instead
Convert every quantity to SI units in the first line of working and carry units through each step. For vector answers, require a magnitude, a unit, and a stated direction as three separate marks in self-marking, and deduct from your own practice attempts when any is missing.
In Chemistry, the candidate balances an equation by adjusting subscripts in a formula rather than coefficients, or writes an ionic equation without cancelling spectator ions, changing the substance being described.
The visual similarity between subscript and coefficient, and the habit of 'making the numbers match' quickly, override the rule that formulae are fixed. Ionic equations are often memorised as strings rather than derived.
What to do instead
Practise a rule-first routine: list the correct formulae first and lock them, then balance only with coefficients, checking each element in a table. For ionic equations, always write the full equation first and strike out spectator ions explicitly before writing the net equation.
In Biology, the candidate answers a 'describe' question with an explanation or an 'explain' question with a list, and uses everyday terms (for example, 'blood goes to the heart to get clean') instead of precise biological terminology.
Command words are not systematically taught as having different mark allocations, and students rely on general knowledge phrasing because precise terms feel risky to spell or recall.
What to do instead
Build a command-word table (state, describe, explain, compare, suggest) with the number of marks each typically attracts, and answer past questions in the exact form demanded. Maintain a terminology list per topic and use each term in a written sentence, not just a definition.
In Economics, the candidate writes a diagram-free answer to a question that requires a supply-and-demand or cost-curve shift, or draws the diagram without labelling axes, curves, and the original and new equilibrium points.
Diagrams are revised separately from written answers, so students do not think to integrate them. Unlabelled sketches still feel complete because the shape looks right.
What to do instead
Treat every diagram as worth explicit marks: axes named, curves labelled, shift arrow shown, and both equilibria marked. In practice, answer each diagram question in the sequence 'draw, label, state the change, state the effect on price and quantity', and self-mark against that checklist.
In Accountancy, the candidate records a transaction on the wrong side or in the wrong account because the analysis of which account is debited and which is credited is skipped, and then forces the trial balance to agree by inserting a suspense figure.
Students memorise journal formats rather than the accounting equation and the debit/credit rules behind them, so unfamiliar transactions have no anchor. Balancing the trial balance becomes the goal instead of a check.
What to do instead
For every transaction, write the accounting-equation effect first (which asset, liability, or capital changes and in which direction) and only then write the journal entry. When a trial balance does not agree, investigate the difference rather than posting to a suspense account, and log each error type found.
In Business Studies, the candidate gives generic textbook definitions and lists of advantages without applying them to the case or organisation named in the question, so marks for application and evaluation are lost.
Definitions are the easiest material to memorise, and case application requires slower reading and judgement. Students also confuse 'state two advantages' with 'evaluate whether this firm should'.
What to do instead
Use a fixed paragraph frame for case questions: name the specific firm and its situation, apply the concept, then give a judgement with a reason. Practise by taking one past case and writing only the application sentences, checking that each one mentions a fact from the case.
In Computer Science, the candidate writes program code with correct logic but faulty syntax - missing indentation, wrong loop or conditional structure, undeclared variables - or traces an algorithm by guessing output instead of tracking variable values line by line.
Code is often read rather than typed and run, so syntax errors are never confronted. Tracing feels unnecessary when the purpose of the program seems obvious.
What to do instead
Write every practice program by hand and then check it against a compiler or interpreter, keeping a personal error log of recurring syntax faults. For tracing questions, use a dry-run table with one column per variable and one row per line executed, and never write output until the table is complete.