Bac F4 Burkina Faso common mistakes
Bac F4 Burkina Faso · Understand the traps and how to avoid them.
In mathematics, the candidate writes the final numerical answer without any intermediate line showing the calculation or the reasoning that produced it, so a correct result cannot be credited when the examiner checks the working.
Candidates practise with answer-only drills and treat the script as a place to record results rather than to demonstrate method; timed practice pushes them to skip lines to save seconds.
What to do instead
Adopt a fixed three-line habit for every calculation: state the formula or property used, substitute the values, then give the result with its unit. In revision, cover the answer key and mark your own script purely on visible steps before checking the result.
In physics, the candidate substitutes numbers into a formula without first converting to SI units, mixing grams with kilograms or centimetres with metres, and then reports the answer with no unit or the wrong one.
Exercises in class often supply values already in convenient units, so the conversion reflex is never built; under exam pressure the candidate grabs the numbers as printed.
What to do instead
Before any substitution, write a short conversion line for each given quantity (for example m = 250 g = 0,25 kg). Make the unit part of the answer line itself and check dimensional consistency of the final expression.
In chemistry, the candidate balances an equation by adjusting subscripts inside formulas instead of placing coefficients in front of them, producing a chemically impossible species.
The visual similarity between subscript and coefficient is never explicitly contrasted, and candidates memorise a few balanced equations rather than the balancing procedure.
What to do instead
Train with a rule stated aloud: subscripts belong to the molecule and may never change; only coefficients in front may change. Balance metals, then non-metals, then hydrogen, then oxygen, and verify atom counts in a small table under each element.
In construction mécanique and dessin technique, the candidate produces a drawing with correct geometry but omits or misplaces the standard elements: centre lines, hidden lines, dimension arrows, section hatching, or the title block.
Classroom time goes to getting the shape right, and the conventions are treated as decoration rather than as the code that makes a drawing readable; line-type drills are rarely timed.
What to do instead
Build a personal checklist of required conventions and run it on every drawing before handing in: axes and centre lines, hidden edges, dimensions with arrows touching the extension lines, hatching at the correct angle and spacing, title block completed. Practise one full drawing per week against that checklist only.
In technology of manufacturing, the candidate confuses cutting speed, feed rate and depth of cut, or applies a formula for turning to a drilling or milling operation without checking which parameter is asked for.
The three parameters are taught together and share symbols and units, and the candidate memorises formulas as strings of letters without attaching each to a physical meaning.
What to do instead
For each parameter, write one sentence in your own words describing what the tool or workpiece actually does, plus its unit. Then solve a mixed set of problems where the question names the operation first, and require yourself to select the formula before writing any number.
In metrology, the candidate reads a vernier calliper or micrometer by taking only the main-scale value and ignoring the alignment of the vernier or thimble scale, or reports a result with more decimals than the instrument can support.
Reading instruments is learned by watching once in a crowded practical session, and the habit of estimating rather than reading the scale persists; significant figures are treated as a formality.
What to do instead
Practise on paper diagrams of scales with known answers, always writing the main-scale reading, the coinciding division, and the product of the division by the least count as three separate lines. State the least count of the instrument at the top of every answer.
In électrotechnique, the candidate applies Ohm's law or a power formula to a whole circuit without identifying which elements are in series and which in parallel, and adds resistances directly across a mixed network.
The formulas are simple enough to be recalled under stress, so the candidate starts calculating immediately instead of redrawing and simplifying the network first.
What to do instead
Force a redrawing step: copy the circuit, mark nodes with letters, and reduce it step by step to a single equivalent resistance before any substitution. Check the result by reasoning about limits, for example whether the equivalent resistance lies between the smallest and largest branch values.
In automatismes, the candidate writes a ladder or logic sequence that works for the normal case but ignores the stop condition, emergency stop, or initial state, so the system would never reset or would run past its end position.
Exercises usually present only the operating sequence, and the safety and initialisation conditions are treated as an afterthought rather than as part of the specification.
What to do instead
Before writing any rung or equation, list the inputs and outputs and then write the full cycle in words including start, end of travel, stop and reset. Test the written logic against each of those cases one by one on paper, and mark which rung handles each.
In français, the candidate answers a question about a text by copying a long passage verbatim or by paraphrasing the whole text, instead of constructing a short justified answer with a quotation and a comment.
Candidates fear missing the expected idea and hedge by reproducing the text; the difference between citing evidence and copying has not been practised under time limits.
What to do instead
Use a fixed answer pattern: state the idea in one sentence, quote only the few words that prove it, then explain in one or two sentences how the quotation supports the idea. Practise on short texts with a strict word budget per answer.
In English, the candidate writes a full composition in the present tense with French word order and literal translations, and answers comprehension questions in single words rather than complete sentences.
Translation from the first language is faster under exam pressure, and classroom practice emphasises vocabulary lists over sentence production, so tense control and word order are never automated.
What to do instead
Keep a personal list of the five errors you actually make, checked against your own past scripts, and proofread every piece of writing once for that list only. For comprehension, always answer in a complete sentence that echoes the question, and practise rewriting ten short French sentences into English each week.
In éducation civique, the candidate answers an essay or discussion question with a list of slogans and moral generalities, with no reference to a concrete institution, text, or example, and no structure of introduction, development and conclusion.
The subject is perceived as common sense requiring no preparation, so candidates rely on vague formulas learned by heart and never practise building an argument.
What to do instead
For each major theme, prepare two concrete anchors: one institution or legal text and one everyday example. Practise writing plans with a clear introduction, two developed parts and a conclusion, and time yourself so the plan is written before the prose begins.