How we mark — the four MYP criteria explained.

Criterion A is about mastery of content: selecting the right mathematical method, applying it correctly, and arriving at a correct answer — both in situations the student has practised and in ones they haven't seen before.

In practice this shows up most often in timed tests. The criterion distinguishes between simple, more complex, and challenging problems, and between familiar contexts (close to what was drilled in class) and unfamiliar contexts (where the student must decide which mathematics applies before calculating).

A student who reliably handles familiar problems at a high level will sit around 5–6. Reaching 7–8 requires demonstrating that same reliability in an unfamiliar context — transferring knowledge, not just recalling it.

Criterion B is assessed through open-ended mathematical investigations. It asks students to apply problem-solving techniques to discover patterns, describe those patterns as general rules, and then verify — and in Years 10–11, justify or prove — those rules.

The key progression from lower bands to upper bands is independence and rigour. At 1–2, a student spots a simple pattern with teacher prompting. At 7–8, the student independently discovers a complex pattern, states it as a precise general rule (often using algebra or a formula), and demonstrates convincingly that the rule always holds.

Investigation tasks are typically open in structure — students are given a starting situation, some data or a diagram to explore, and asked to work mathematically toward a general conclusion. Good communication (Criterion C) is essential alongside Criterion B work.

Criterion C is about the quality of mathematical writing — not the final answer, but how the student records their thinking along the way. It covers notation, terminology, choice of representation (diagram, graph, table, equation), and whether the working is logical enough for someone else to follow without guessing at missing steps.

Criterion C is almost always co-assessed with another criterion. Every test is partly a communication task; every investigation is partly a communication task. A student who gets the right answer but shows no working, uses inconsistent notation, or jumps over steps is limited in Criterion C regardless of their score on A or B.

Parents often notice Criterion C first on a report when they see a student with strong arithmetic but poor marks: the likely issue is working that is too compressed, lacks labels on diagrams, or uses informal language where mathematical terminology is expected.

Criterion D is about mathematical modelling: taking a real-world situation, identifying which mathematical tools are relevant, applying those tools to reach a solution, and then stepping back to evaluate how good that solution actually is in context.

A key feature of Criterion D tasks is that the student must make choices — which variables matter, what assumptions to simplify, which model fits the data. There is rarely one correct method. What the criterion rewards is thoughtful selection, accurate application, and honest reflection on the model's accuracy and limitations.

At 7–8, a student doesn't just get a number — they explain how accurate it is, acknowledge where the model breaks down, and say clearly whether the answer makes sense given the real-world context it came from.