You know how to do the question. You've done ten like it. But on the exam paper — or worse, on past papers — you drop a mark or two. Not because you didn't know the maths, but because of something small: a sign you missed, a digit you copied wrong, a unit you forgot to write, or a final simplification you skipped.
These are the cheapest marks you'll lose all term. And they're almost entirely preventable.
Why you're losing marks (and why it feels impossible to stop)
In class or at home, you have unlimited time. You can re-read questions, double-check your work, think through each step. On exam day you don't. You rush, because you know the next five questions are waiting. Your brain runs on autopilot, and autopilot occasionally skips a step or misreads a detail.
The issue isn't understanding. It's exam-day speed under pressure. Most revision tackles "I don't understand this", when for many students the problem is "I understand it but lose the mark anyway".
The mark-by-mark audit: find your specific mistakes
Don't just do past papers and move on. After every paper — especially full mocks — go through every lost mark with a single question: Why did I lose that?
Write each one down in one of these categories:
- Reading error: You misread the question or the number (3 read as 8, "not" missed, units overlooked).
- Careless arithmetic: 5 × 7 calculated as 35 but written as 38, or 150 ÷ 5 done correctly in your head but written as 30.
- Missing step: You skipped simplifying the final answer, forgot to write the unit, or didn't give the answer to the right number of decimal places.
- Formula mix-up: Used the right formula but plugged in the numbers wrong, or forgot a term.
- Logic skip: Jumped to the answer without showing working that the examiner needs to award marks.
After 3–4 past papers, you'll see a pattern. Most students have a "signature mistake".
Stop your specific mistake: targeted prevention
If you keep misreading questions: Before you write anything, circle or underline the key numbers and the exact thing being asked. Then write it down separately: "Find the volume, to 2 decimal places, in cm³." Misreading won't be a slip anymore — it'll be deliberate.
If you keep making arithmetic mistakes: Do your rough working bigger and cleaner. Sound out steps aloud as you write them. 5 × 7 = 35, so you hear yourself say "thirty-five" and then you write 35, and the disconnect gets caught immediately. This sounds silly but it works.
If you skip the final step: Make a habit: answer written? Reread the question. Is that what it asked for? Is the unit there? Is it simplified/to the right decimal place? Tick the checklist before you move on.
If you mix up formulas: Before the exam, write down every formula you might need. During the paper, if you use a formula, point to it. You'll catch it if you've grabbed the wrong one.
If you skip working: In revision, do every past paper question as if the examiner can only see the answer if you show working. Use full sentences where needed: "Angle ABC = 180 − 65 = 115°" not just "115°". When this becomes your habit, exam working won't feel like extra effort.
The 90-second check
When you finish a past paper, don't just check the answers. Spend 90 seconds on each question you're unsure about: re-read the question, check your working, check your arithmetic, check your final answer. You'll catch most of your own mistakes.
In the real exam, if you finish early (and you should, with a well-paced paper), use your spare time this way instead of re-working everything.
Practice the exam conditions
Your revision timetable should include full past papers done under timed conditions, with no notes, no calculator (where applicable), exactly like the real thing. This trains you to work at exam speed without the speed being an excuse for mistakes. Your brain gets comfortable with the pace, and careless errors drop naturally.
Do one full paper per week in the month before your exams, even if you feel ready. Your fingers and brain need to practice the real thing.
What to do this week
- Do one past paper under timed exam conditions.
- Mark it and audit every single lost mark — put each in one of the five categories above.
- Identify your signature mistake (the one that appears most).
- Do one more paper the same week, implementing your targeted prevention for that specific mistake.
- Check if the mark count improved. It usually does, immediately.
These aren't deep conceptual mistakes. They're shallow habits, and shallow habits are quick to break with deliberate practice.