Many IGCSE Physics students understand the ideas well in class, then lose marks in the exam because their answers do not match what the mark scheme rewards. A student can know that a resistor's resistance rises with temperature for a metal, yet write 'the wire gets hotter' and stop, when the examiner wants a reason about electrons and lattice vibrations. The fix is not more hours of reading. It is learning to spot the specific habits that cost marks, then practising against the published criteria until those habits disappear.
Losing marks on units before the physics begins
Units are the most common source of avoidable errors. A current written as 250 when the question gives it in milliamperes, or a length left in centimetres when the formula needs metres, will produce an answer that is wrong by a factor of a hundred or a thousand. Students often do the arithmetic correctly and still lose the mark because the final unit is missing or incorrect.
A simple routine helps. Before you substitute any value, write every quantity with its unit, convert anything that is not in SI, and check that the final unit makes sense for the quantity you calculated. If you are working out a speed and the answer comes out in kilograms, something has gone wrong earlier.
Answers that describe but never explain
The command word tells you what kind of answer the examiner expects. 'State' asks for a short fact. 'Describe' asks for what happens, in order. 'Explain' asks for why it happens, and that means a cause and an effect linked by a physical principle. Many students write a correct description for an explain question and receive only part of the credit.
Look at a question about why a parachutist eventually reaches a steady speed. A describe answer says the speed stops increasing. An explain answer says that air resistance increases with speed until it equals the weight, so the resultant force becomes zero and the velocity stays constant. The second answer is longer, but it is the one the mark scheme is written for.
Using the words the mark scheme expects
Physics has precise vocabulary, and examiners check for it. Confusing heat with temperature, mass with weight, or frequency with wavelength is treated as a conceptual error even when the rest of the answer is sound. Build a short personal glossary as you revise and check each definition against your textbook or the syllabus wording.
Calculations that are correct but not set out for marks
In structured questions, examiners often award a method mark for the correct equation even when the final number is wrong. Students who jump straight to a number, or who write the answer with no formula, lose those method marks. Writing the equation first, substituting values with units, and then rearranging is not wasted time. It is how you earn credit when a small slip has occurred.
Significant figures also matter. Your answer should usually match the precision of the data in the question. Giving a result to six decimal places when the data has two significant figures signals that the answer is not understood, even if the calculation is right.
Reading graphs and circuit diagrams with less care
Graph questions are where careful reading pays off. Check the axis labels and units before you read any value. When you calculate a gradient, use a large triangle on the line itself rather than two points from the data table, and show the working. Students who ignore a non-zero intercept, or who read a scale marked in steps of two as if it were in ones, make predictable errors.
Circuit questions reward the same discipline. Learn the standard symbols for cells, lamps, thermistors and LDRs, and trace the current path before you attempt any calculation. In a series circuit, the current is the same throughout; in a parallel branch, the voltage across each branch is the same. Writing these two facts down at the start of a problem prevents many errors.
Managing time and attention across the paper
A student who spends eight minutes on a one-mark question has taken time from questions worth far more. Work out roughly how many minutes each mark is worth, and move on when you reach that limit. Return to skipped questions at the end. Leaving a gap is better than abandoning a whole section.
How INACADEMICS helps students fix these habits
At INACADEMICS, the teaching is organised around the published assessment criteria, so the habits described above are corrected directly rather than left for the student to discover. Our IGCSE sessions for Grades 9 and 10 are taught by subject specialists who work with IGCSE mark schemes and past papers, and who show students what a full-mark answer looks like for each command word. Batches are kept small, with four to eight students, so a teacher can see the working on each page and correct a units habit or a vague explain answer in the moment.
We begin with a short diagnostic and a per-subject plan, so we know which mistakes a particular student makes most often. Weekly worksheets give that student repeated practice on those points, monthly mock papers test them under exam conditions, and parents receive regular updates tracked against the plan. The aim is that by the time the real paper arrives, the student's answers already follow the mark scheme.
Frequently Asked Questions
Which mistake costs IGCSE Physics students the most marks?
There is no single answer for every student, but unit errors and incomplete explain answers are among the most common. Both can be fixed with deliberate practice. A good diagnostic will show which of these patterns applies to a particular student.
How can I tell whether my answers are too short?
Compare your answer with the number of marks allocated. A three-mark explain question that you answer in one sentence is almost certainly missing points. Practising with past papers and checking your answers against the mark scheme is the most reliable way to see the gap.
How does INACADEMICS deal with a student who keeps making the same error?
We track each student against their plan. If the same mistake appears in weekly worksheets and monthly mocks, the teacher adjusts the next block of practice to target it directly, and parents are told what has changed and why. Small batches make this kind of individual feedback practical.
Is IGCSE Physics tuition useful if my child is already doing well at school?
It can be. A student who is already strong often gains most from polishing command word technique and exam timing, which is where a few marks are usually lost. A free counselling conversation can help you decide whether this is worth doing.
Wrap-up
Most IGCSE Physics marks lost in exams come from habits rather than gaps in understanding: careless units, descriptions where explanations were needed, calculations without visible method, and time spent in the wrong places. Each of these can be corrected with focused practice against the mark scheme. If you would like to talk through your child's strengths and the habits that need work, you can arrange free counselling by calling or messaging WhatsApp on +91 9014010410, or visit our centre at 117, 1st Floor, Raichandani Business Bay, above Karachi Bakery, Kokapet.