Three subjects, three different difficulties
Physics
The usual problem is not the formula but the modelling: deciding what is being asked, which quantities are available, and what the answer should look like before calculating. Students who leap straight to an equation get stuck the moment the question is phrased unfamiliarly.
Chemistry
Moles, concentrations, stoichiometry and organic mechanisms. Much of the difficulty is bookkeeping: distinguishing a quantity from its symbol, tracking units through a calculation, and knowing which figure the question actually wants.
Biology and SVT
Definitions are necessary but never sufficient. Papers test whether a student can read a graph or a diagram, describe precisely what it shows, and then connect that observation to a mechanism from the course. Those are separate skills, and they are separately teachable.
A worked example: units carry meaning
A car covers 150 km in 2 h 30 min. What is its average speed?
2 h 30 min = 2.5 h
v = d / t = 150 / 2.5 = 60 km h⁻¹
The arithmetic is trivial. Two things are not. First, the conversion: writing 2.5 rather than 2.30 is where a large share of lost marks live. Second, the interpretation — 60 km h⁻¹ is an average, and the car may never have travelled at that speed for a single second. A question asking “was the car speeding?” cannot be answered from this figure alone.
In a lesson we make the student state what they are looking for and in which unit before touching a calculator, then explain what the result means afterwards. The correction covers that whole path, not just the number.
Reading a document, in biology and beyond
A large part of biology and SVT assessment is document work: a graph, a table, an annotated diagram. Students lose marks by mixing two things that examiners keep apart.
- Observation — what the document literally shows. “Between 0 and 20 minutes the concentration falls from 8 to 2 mmol·L⁻¹.” Axes, units and a numerical range.
- Interpretation — what you conclude from it, using the course. “This is consistent with the substrate being consumed by the enzyme.”
Writing the second without the first is the most common way to lose marks on a question a student actually understands. Démi, who trained as a life-sciences engineer and holds a degree in physics and chemistry, works on precisely this separation.
French curriculum and international syllabuses
The scope of French physique-chimie and SVT does not map cleanly onto IGCSE Combined Science or IB Biology. Practical write-ups, the weight given to the experimental method, and the expected level of mathematical treatment all differ. We match the tutor to the syllabus your child sits, and teach in the language they are examined in.
