Free Guide · IB Math
After 7+ years tutoring IB Math, I've seen the same patterns in how students gain and lose marks. This guide gives you the strategies that work, for both AA and AI, HL and SL.
Most students believe losing marks in IB Math means not knowing the maths. That's rarely the full story. In my experience, a significant portion of lost marks come from how students present their work, not from gaps in their mathematical knowledge.
The IB markscheme is designed to reward clear, structured thinking. Understanding how it works, what types of marks exist, how follow-through marks work, what different command terms demand, lets you get more marks from the maths you already know.
Before any strategy, you need to understand the three types of marks IB examiners award.
| Mark | Name | What you need to do | Can you lose it? |
|---|---|---|---|
| M | Method | Show the correct method or formula, even with arithmetic errors | Only if you show nothing or the wrong method |
| A | Accuracy | Give the correct numerical answer, following correct method | Yes, for arithmetic errors or wrong final answer |
| R | Reasoning | Write a valid justification, explanation, or logical argument | Yes, if you give only a number without explanation |
| ft | Follow-through | Use a wrong answer from a previous part correctly in the next part | Only if you apply your own wrong answer inconsistently |
01
Never write only a final answer, even for questions that seem simple. Write the formula you're using, the substitution, and the intermediate step before the answer. A calculator result with no working shown earns zero method marks, and if the answer is wrong, you get nothing. One extra line of working can recover 1–2 marks.
02
The command term tells you exactly how much to write. "Write down" means no working needed. "Show that" means every logical step must be visible. "Justify" means you need to explain with words and reasoning, not just calculate. Misreading the command term is one of the most common, and most avoidable, ways to lose marks. See our full IB Math command terms guide for every term explained.
03
If you make an error in part (a), don't give up on parts (b), (c), and (d). The markscheme awards follow-through marks when you apply your wrong answer consistently and correctly in subsequent parts. Always attempt every part of a question, even if a previous part went wrong. Write clearly what value you are using, examiners need to see you know the method.
04
These are different command terms with different expectations. A sketch needs to show the correct shape and all key features (intercepts, asymptotes, turning points) labelled with coordinates. A draw requires accuracy and scale. For sketches: always label the x-intercepts, y-intercept, any horizontal/vertical asymptotes, and the coordinates of turning points. Missing labels costs marks.
05
When a question says "hence", you must use the result from the previous part. If you couldn't complete the previous part, write: "Using the result from part (a): [write the given result]" and then continue. Examiners see this constantly and award the marks. Don't skip a "hence" question just because the previous part was incomplete.
06
R marks (Reasoning marks) are awarded specifically for written explanation. A number or calculation alone will not earn an R mark. When you see "justify", "explain", or "comment": write at least one full sentence referencing the mathematical reason. Example: "The function has a minimum at x = 2 because f''(2) = 4 > 0, confirming it is a local minimum." Reference the test or rule you applied.
07
IB Math papers reward students who attempt the most questions. A student who answers 90% of questions partially will almost always outscore one who answers 70% of questions perfectly. In the exam: if you are stuck for more than 3 minutes on a sub-part, mark it, move on, and return at the end. The marks available per minute are highest on questions you can actually do.
The two papers test slightly different skills and demand different approaches.
The two courses have different emphases. The mark-maximising strategies apply to both, but the priorities differ.
Algebra and proof are central. Show algebraic steps fully, partial credit is available for each correct manipulation. "Show that" questions are common and all marks come from the working. For calculus questions, write derivatives and integrals clearly before substituting values.
Context and interpretation are tested heavily. Always include units in answers where relevant. For statistics questions, state your hypotheses clearly (H₀ and H₁) before testing. For modelling questions, state the model you're using and interpret the parameters in context.
These are the patterns I see again and again across hundreds of student papers.
Writing only the GDC answer
Typing into the calculator and writing the final number earns 0 method marks if the answer is wrong.
Fix: Write the equation you're solving before using the GDC.
No +C on indefinite integrals
Forgetting the constant of integration is an automatic accuracy mark loss. One mark lost every single time.
Fix: Build the habit of writing +C before you simplify.
Skipping parts after an error
Students give up on (b), (c), (d) because they got (a) wrong. Follow-through marks are available.
Fix: Always attempt subsequent parts using your answer from (a).
Not labelling graph features
Drawing the correct shape but failing to label intercepts or asymptotes costs 1–2 marks per sketch.
Fix: After any sketch, check: intercepts? asymptotes? turning points? all labelled with coordinates?
Rounding too early
Rounding intermediate values causes accumulated error. The final answer may be wrong even with correct method.
Fix: Keep at least 4 significant figures in intermediate steps. Round only the final answer.
No reasoning on "justify" questions
Writing only a number for a "justify" question earns 0 reasoning marks, even if the number is correct.
Fix: Every "justify" needs at least one sentence explaining the mathematical reason.
Print this and review it the night before your IB Math exam.
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