One paper. Roughly the same mistakes, every series.
CIE examiners write reports after every series. We read all of them from 2021 to 2025 — every variant — and the same handful of errors come up every single time. Master those, and you've protected most of the marks in Paper 5.
Use The Rules as a reference. Drill yourself in Drill Mode. After every practice paper, run the Self-Audit to find what slipped.
Self-Audit completion
If you only fix five things…
Ranked by how many series each error appeared in. Each one shows up almost every paper. Click any item to jump to the rule.
- Best-fit line drawn dot-to-dot. Graph work
- Best-fit line forced through the origin. Graph work
- 5% / 10% tolerance rule not applied when comparing values. Conclusions
- Conclusion method missing — a prediction is written instead. Planning
- Generic sources of error: "parallax", "human error". Sources of error
Browse by question type
Every rule, every common error, every examiner quote.
Filter by topic or search for a keyword. Each rule is grounded in actual examiner reports — the wording is theirs, not ours.
Test yourself on the things examiners actually mark.
15 questions drawn from the most common errors across 5 years of examiner reports. Pick a mode and go.
Ready when you are.
Choose a topic, or attempt them all.
After every practice paper, tick off what you got right.
For each box you can't tick, jump back to the relevant rule. Your progress is saved in this browser.
25 most-criticised mistakes, ranked.
Ordered by how many series each error appeared in across Papers 5 and 6, 2021–2025. The higher up the list, the more marks the average candidate loses to it.
One email when a new trainer goes live.
No spam, no daily nudges. Just a note when Paper 4, Paper 6, or the 9702 trainers are ready — plus the occasional examiner tip the week before an exam window.