Lost marks tell you which skill to repair, but only if you sort them first. A calculation mark and an explanation mark call for different practice.
This page helps when you study hard and your marks still move around. The mistake log and paper-error review is the tool that puts this into practice.
What does it sound like when this happens?
Students describe it in similar words.
- “I revised calculations and then lost marks on explanations.”
- “Every paper feels different, so I do not know what to fix.”
- “I keep reading everything again and nothing improves.”
What is usually behind it?
Revising the whole syllabus again treats all lost marks as one problem. In fact, marks are lost for at least three different reasons, and each needs its own repair.
The other cause is reading the marks lost as a total, not as types. A total of 12 marks lost gives no direction.
How do you sort lost marks?
Use three buckets.
| Bucket | What it means | Repair |
|---|---|---|
| Calculation | Method correct, unit or arithmetic slip, or wrong method | Units checklist, or a repair of the mole skill behind it |
| Explanation | Correct idea, but missing the particle, force or reason | Marking-point practice, as in the exam guide |
| Recall | Fact, colour, test or definition not known | Short spaced recall, using flashcards or the spaced recall planner |
Worked example: a fictional paper review
A student reviews a paper with 12 marks lost. Sorting them gives:
| Bucket | Marks lost | Examples |
|---|---|---|
| Calculation | 4 | 2 marks for missing units, 2 marks for using the mass ratio instead of the mole ratio |
| Explanation | 6 | Answers that named the property but not the force or the particles |
| Recall | 2 | A gas test and a colour forgotten |
The largest share is explanation: 6 of the 12 marks, which is half. The next paper should start there.
The two calculation marks for the wrong ratio show a deeper issue than units, so the plan has two parts. First, fix units with a checklist. Second, repair the ratio skill with repairing mole calculations before mixed chemistry questions.
What can you do this week?
- Take your two most recent papers.
- List every lost mark and assign it to a bucket.
- Count each bucket and choose the largest.
- Practise only that bucket for a week, then test on fresh questions.
The SPM Chemistry exam guide shows how to structure explanations. If the marks look scattered, the prerequisite gap finder can point to a basic skill.
When might one-to-one tuition help?
If you cannot decide which bucket a lost mark belongs in, a teacher can sort them with you and explain each one. The sorting is faster with someone who knows what the mark scheme rewards.
See online one-to-one Chemistry tuition for how starting works. Bring your two marked papers to that conversation.