Bac F1 Burkina Faso common mistakes
Bac F1 Burkina Faso · Understand the traps and how to avoid them.
In mathematics, the candidate computes a numerical value and writes it as the final answer without stating the unit or the exact form when the question asks for an exact result (for example giving 1.41 instead of √2, or omitting the unit of a length or area).
Baccalauréat mathematics papers habitually separate the calculation from the conclusion; candidates trained on multiple-choice drills stop at the number and forget that the marking scheme awards a point for the justified exact value and the correct unit.
What to do instead
Adopt a fixed two-line conclusion: line one gives the exact value (fraction, radical, π multiple), line two gives the decimal approximation with unit and rounding stated. Practise on past-style exercises where the instruction says 'donner la valeur exacte puis une valeur approchée'.
In mathematics, the candidate starts a proof of a property (monotonicity, convergence, divisibility) by assuming the conclusion, or writes 'on voit bien que' in place of a logical argument.
Time pressure and memorised model answers lead students to reproduce the final sentence of a corrected exercise without the reasoning chain that earns the marks; the underlying logical structure (hypothesis, property used, conclusion) was never internalised.
What to do instead
Train a three-column reasoning template: what is given, which theorem or definition applies and why its hypotheses are satisfied, what follows. Redo every corrected exercise by rewriting only the justification column, then compare with the official correction.
In physics-chemistry, the candidate applies a formula without converting to SI units, mixing grams with kilograms, centimetres with metres, or minutes with seconds, and reports an absurd magnitude without noticing.
School exercises often use convenient units, so the reflex of converting before substituting is weak; students also copy the numerical data straight from the statement into the calculator.
What to do instead
Impose a written conversion step before any substitution (mass in kg, length in m, time in s, temperature in K), and add a plausibility check: compare the order of magnitude of the result with a known reference value before writing the answer.
In physics-chemistry, the candidate confuses the balanced equation with the reaction mechanism or forgets to balance charges and atoms in an ionic half-equation, then carries the error into the stoichiometric calculation.
Balancing is treated as a formality rather than the basis of the mole calculation; students balance atoms but ignore charge conservation in redox or acid-base equations.
What to do instead
Verify every equation with an explicit checklist written at the side of the page: each element balanced, total charge equal on both sides, then state the stoichiometric coefficients used in the mole ratio. Do five balancing drills per week across combustion, acid-base and redox.
In construction mécanique / dessin technique, the candidate produces a drawing with correct geometry but omits or misplaces standards: no scale indication, wrong line types for hidden edges, missing or duplicated dimensions, dimensions placed inside the view.
Students concentrate on the shape and treat standardisation as decoration; they have not memorised which line thickness and which dimensioning rule applies to each feature.
What to do instead
Build a one-page personal standards sheet (line types, arrow style, dimension placement, scale box, title block fields) and apply it as a final self-check on every drawing before submission; grade your own drawings against the sheet, not against the model answer.
In construction mécanique / dessin technique, the candidate misreads a projection or section view, placing a feature on the wrong face, or draws a sectional view without hatching the cut material correctly.
Weak spatial rotation skill: students read each view in isolation instead of projecting features across views, and they do not apply the convention that hatching indicates material actually cut by the plane.
What to do instead
Practise systematic cross-view projection: pick one feature, trace its alignment lines into the other views before drawing anything. For sections, first draw the cutting plane on the main view, then hatch only the cut areas, leaving shafts and holes unhatched.
In technologie de construction / mécanique appliquée, the candidate calculates reactions or internal forces using equilibrium equations but ignores a support condition, a redundant support, or the direction convention of moments.
The free-body diagram is skipped or drawn incompletely; sign conventions for moments are chosen ad hoc and changed midway through the calculation.
What to do instead
Always draw and label a complete free-body diagram first, state the sign convention in writing at the top of the solution, and check the result by taking moments about a second point or verifying that the sum of reactions equals the applied load.
In technologie de construction / mécanique appliquée, the candidate selects a material or a section without linking the mechanical characteristic (yield strength, modulus, second moment of area) to the actual loading case, and gives a technical answer with no justification.
Students memorise data tables but not the selection logic; they answer 'acier parce que c'est résistant' instead of comparing stress to allowable stress or deflection to a limit.
What to do instead
Structure every technology answer as: loading identified, governing criterion chosen (strength, stiffness, durability), value computed or looked up, comparison with the admissible limit, conclusion. Train on short justification questions of three to five sentences.
In French, the candidate answers a comprehension question by copying a long passage from the text instead of reformulating, and in the production écrite writes a long introduction and runs out of space before developing the argument.
Copying feels safe and saves time; students have not been taught to plan a two- or three-part outline before writing, so the composition is improvised and unbalanced.
What to do instead
For comprehension, answer in one sentence using your own words and quote only a short fragment as evidence. For the production écrite, spend five minutes on a plan with two or three ideas and one example each, then write to the plan, reserving time for re-reading.
In English, the candidate translates word for word from French, producing errors of tense, agreement and preposition, and answers the reading comprehension with a full sentence copied from the text.
Limited active vocabulary and a habit of composing in French then transposing; the tense system and article use differ enough that literal transfer fails.
What to do instead
Learn set phrases and collocations rather than isolated words, and write short answers using a fixed frame (subject + verb + complement) built from the text's own key words but recombined. Keep an error log of your ten most frequent mistakes and check it before each practice paper.