Paper 3 is the paper most HL students see the least of during the course — and the one that catches the most people off guard on exam day. Unlike Paper 1 and Paper 2, which follow a familiar rhythm of short, separated questions, Paper 3 asks you to work through one or two long, scaffolded problems that build on each other. Get the structure and get comfortable with the flow, and it stops feeling unpredictable.
What Paper 3 actually tests
Paper 3 (HL only, both AA and AI) is worth 20% of your final grade and runs for 1 hour. You'll typically see two extended, multi-part questions, each built around a single scenario that unfolds step by step. Instead of testing isolated skills, it tests whether you can carry an idea from one part of a problem into the next — using an earlier answer, or a pattern you just derived, to solve what comes after it.
| AA HL | AI HL | |
|---|---|---|
| Weighting | 20% | 20% |
| Time | 1 hour | 1 hour |
| Marks | 55 | 55 |
| Calculator | Allowed (GDC) | Allowed (GDC) |
| Focus | Investigation-style problem solving, patterns, proof | Modelling, technology-driven exploration |
Why it feels different from Paper 1 and 2
The biggest adjustment is pacing. In Paper 1 or 2, if a question stumps you, you move on — it's isolated, and the next question starts fresh. In Paper 3, each part is a stepping stone. If you misread part (a), the error can quietly follow you through the rest of the question. That's not a design flaw; it's the whole point. Examiners are checking whether you can build an argument, not just execute one calculation.
Students often panic when a later part of the question doesn't match the number they expected. Before assuming your earlier work is wrong, re-read what the new part is actually asking — sometimes it introduces a small twist (a new condition, a different variable) rather than continuing the exact same calculation.
How to practise effectively
- Do full questions, not fragments. Paper 3 practice loses most of its value if you only do part (a) of each question. The skill being tested is carrying a thread through multiple parts — so simulate that every time.
- Time yourself per question, not per part. Aim for roughly 30 minutes per extended question. If you're consistently running over, that's a signal to work on recognising the structure faster, not necessarily on raw calculation speed.
- Get comfortable saying "let me define this clearly." Many Paper 3 questions reward you for stating assumptions or setting up notation explicitly before diving into calculation — examiners are looking for a clear line of reasoning, not just a final number.
- Review the mark scheme part by part. After attempting a full question, check where marks were earned for method versus final answer (M marks vs A marks) — this tells you whether your reasoning would have scored even if your final number was off.
What good preparation looks like in the final weeks
Six to four weeks out, most students benefit from doing one full Paper 3 question every few days rather than cramming several in one sitting. Because each question tends to be a self-contained "investigation," spacing them out gives you time to reflect on where your reasoning broke down — which matters more here than in Paper 1 or 2, where each question is independent.
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✦ Try it freeFrequently asked questions
Is Paper 3 only for HL students?
Yes. Paper 3 exists only for the Higher Level route, in both AA and AI. SL students sit only Paper 1 and Paper 2.
Can I use a calculator on Paper 3?
Yes, for both AA HL and AI HL, a graphic display calculator (GDC) is permitted throughout.
How many questions are on Paper 3?
Typically two extended questions, though the exact number can vary slightly by session — always check the most recent subject guide for confirmation.