IB MYP Math Criterion C — Communicating (8 Marks)
Criterion C assesses how well you communicate mathematical ideas, reasoning, and solutions. It rewards students who use appropriate mathematical language, move fluently between different forms of representation (tables, graphs, equations, diagrams), and present their work in a clear, organised way. Worth 8 marks, it affects every task you submit.
What Does Criterion C Assess?
The IB defines Criterion C as the ability to:
- Use appropriate mathematical language (notation, symbols, terminology)
- Use multiple forms of mathematical representation (formulae, diagrams, tables, graphs, models)
- Move between different representations effectively
- Communicate mathematical reasoning clearly and in a logical sequence
- Organise information using a logical structure
MYP Criterion C Mark Descriptors
| Marks | Descriptor |
|---|---|
| 0 | The student does not reach a standard described by any of the descriptors below. |
| 1–2 | The student is able to use limited mathematical language; use limited forms of mathematical representation; communicate through lines of reasoning that are difficult to interpret. |
| 3–4 | The student is able to use some appropriate mathematical language; use different forms of mathematical representation; communicate through lines of reasoning that are able to be understood, although these are not always clear. |
| 5–6 | The student is able to usually use appropriate mathematical language; usually use different forms of mathematical representation; move between different forms of representation with some success; communicate through lines of reasoning that are clear but not always fully coherent. |
| 7–8 | The student is able to consistently use appropriate mathematical language; use different forms of mathematical representation; move effectively between different forms of representation; communicate through lines of reasoning that are complete, coherent, and concise. |
What “Appropriate Mathematical Language” Means
This includes correct use of:
- Mathematical symbols (=, ≠, ≤, ∴, etc.) rather than informal equivalents (“approx” instead of ≈)
- Technical terms used correctly (gradient, factorise, congruent, perpendicular)
- Proper notation for functions, sets, vectors, and statistical measures
- Units stated consistently (cm², km/h, degrees) wherever measurements appear
How to Score 7–8 on Criterion C
- Use mathematical notation throughout — not just in calculations but in explanations too
- Include at least one diagram, graph, or table wherever they add clarity
- Explicitly state what each step achieves — “therefore”, “this means that”, “which shows that”
- Organise your work with clear headings and logical flow from one step to the next
- Review your work for missing labels, undefined variables, or ambiguous notation
Common Criterion C Mistakes
- Writing in prose without using any mathematical notation
- Producing a graph but not labelling axes or units
- Skipping steps in reasoning so the logic is hard to follow
- Using informal language (“it gets bigger”) instead of precise terms (“increases proportionally”)
MYP Math Communication Support in Dubai
Mr. Ahmad specifically coaches students on mathematical communication — one of the criteria that is easiest to improve with targeted feedback. Many students have correct working but lose marks because their presentation is unclear. Contact us today to discuss MYP Math tutoring in Dubai.
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