Mali Bac TSE common mistakes
Mali Bac TSE · Understand the traps and how to avoid them.
In mathématiques, the candidate applies a formula (dérivée, intégrale, suite géométrique) without first checking its conditions of validity, e.g. using u/v derivative rule when the denominator can vanish, or summing a geometric series with |q| ≥ 1.
Baccalaureate training rewards formula recall; under time pressure candidates pattern-match the surface of the exercise to a memorized recipe instead of reading the hypotheses (domain of definition, sign of q, continuity) that the statement carefully provides.
What to do instead
Before writing any formula, force yourself to write one line: 'Conditions: ...' listing domain, sign, and continuity requirements. Do this in every practice exercise until it becomes automatic, then check the final answer against the stated domain.
In physique, the candidate substitutes numerical values into an equation before establishing the literal expression and checking dimensional homogeneity, so a units error (cm instead of m, g instead of kg, minutes instead of seconds) goes undetected.
Students are used to 'getting the number' as the goal and skip the algebraic step; calculators accept any input, so nothing signals the mistake until the grade comes back.
What to do instead
Impose a two-step written protocol: literal expression first, then a units check (analyse dimensionnelle) on that expression, then substitution with all quantities converted to SI. Practise 10 exercises doing only the literal-plus-units step to build the reflex.
In chimie, the candidate balances an equation by adjusting coefficients but leaves the charges unbalanced in ionic half-equations (oxydoréduction), or forgets to add H⁺/H₂O or OH⁻/H₂O to close the oxygen and hydrogen balance.
The method is taught as a sequence of steps, and candidates compress it under exam pressure, treating charge conservation as optional because it does not change the visible atom count.
What to do instead
Use a fixed written checklist for every half-equation: atoms → oxygens with H₂O → hydrogens with H⁺ (or OH⁻ in basic medium) → charges with electrons. Verify the electron count matches between the two half-equations before summing them.
In biologie/SVT, the candidate describes a document (graph, micrograph, experiment table) narratively ('la courbe monte puis descend') instead of extracting the measured variable, its values, and the biological conclusion it supports.
Candidates confuse 'saying what is on the document' with 'interpreting it'; the reading step feels like the answer, so they stop before linking observation to mechanism or to the problem posed.
What to do instead
Structure each answer in three explicit sentences: 'On observe que [variable] passe de X à Y entre [values]', 'Or [knowledge]', 'Donc [conclusion answering the question]'. Practise on past document-analysis questions with a timer.
In français, the candidate writes a dissertation or commentaire composé that paraphrases the text or lists ideas without a thesis, and builds paragraphs with no explicit argumentative link (connecteurs logiques) between claim, example, and interpretation.
Students often have ideas but no rehearsed paragraph architecture, so under exam conditions they produce descriptive prose; they also under-invest in analysing the subject's key words before starting.
What to do instead
Before writing, spend 10 minutes producing a plan with one thesis sentence and one claim per paragraph. Train the paragraph template: idée → exemple précis cité → analyse → lien avec la thèse. Do timed paragraph-only drills rather than full essays.
In philosophie, the candidate treats the subject as an invitation to give a personal opinion or a list of authors' doctrines, without problematizing the notions and without a progression that resolves a tension.
The 'dissertation' format is unfamiliar in its demands; candidates think volume and references earn marks, whereas the grader looks for a formulated problem and a coherent conceptual movement.
What to do instead
For every subject, write the 'problématique' first: identify the apparent obvious answer, then the objection that makes it problematic. Build a three-part plan (thèse, antithèse, dépassement) and check each part actually answers the reformulated question.
In anglais, the candidate translates word-for-word from French, producing calques ('I have 18 years', 'since two years', 'explain me'), and answers comprehension questions by copying a full sentence from the text rather than reformulating.
The habit comes from classroom translation exercises and from fear of grammar errors; copying feels safe and reformulating feels risky, but copying earns no comprehension credit.
What to do instead
Keep a personal list of the 20 most frequent calques with their correct English forms and drill them weekly. For comprehension, practise answering in your own words in one sentence, then check against the text for accuracy.
In histoire-géographie, the candidate produces a narrative chronological account or an inventory of facts without organizing them into a structured plan (thèmes/échelles), and in geography ignores the scale of analysis requested by the subject.
Revision is often fact-memorization, so the exam becomes a memory dump; the method of building a plan from the subject's key words and the required scale is rarely rehearsed.
What to do instead
Underline the subject's key words and the requested scale (local, national, mondial) before planning. Practise producing only plans (introduction with problématique, two or three parts with titles) for 15 past subjects, then write one full essay under time.
Across scientific subjects, the candidate skips the required diagram or schematic (coupe géologique, schéma d'un mécanisme, circuit électrique) or draws it without a title, legend, and labelled parts, losing the structured marks attached to it.
Diagrams are perceived as decoration rather than as an assessed communication tool, and they are time-consuming, so they are dropped when the clock runs short.
What to do instead
Memorize the marking grid for diagrams (titre, légendes, orientation/échelle, propreté) and reserve explicit time for them in your timing plan. Redraw the five most frequent schemas from memory weekly until each takes under three minutes.
Across all subjects, the candidate manages time badly: spending too long on one exercise, leaving the last question or the whole last part untouched, and not re-reading the subject's instructions (nombre de questions, choix obligatoire entre deux sujets, calculatrice autorisée).
Anxiety drives over-investment in the first question, and candidates rarely rehearse under real timing; they also read the subject once and never return to the instructions.
What to do instead
Do full timed mock exams with a written timing budget per exercise, and adopt the rule: if stuck for more than five minutes, mark it and move on. In the first two minutes, list the questions and points, and re-read the instructions before starting.