MYP Maths: Ratio & Proportion FAQ

Ratio and proportion in MYP 1-3 is assessed mainly through Criterion A (Knowing and Understanding) and Criterion D (Applying Mathematics in Real-Life Contexts), using unit tests, investigations and real-world problems like recipe scaling or map ratios rather than isolated drill questions.

Criterion A checks whether you can select and apply the correct ratio method and get an accurate answer. Criterion D checks whether you can transfer that method to an unfamiliar real-life situation and explain why your approach makes sense — that's usually where marks are lost.

MYP 1-3 ratio and proportion covers simplifying ratios, sharing amounts in a given ratio, direct and inverse proportion, scale drawings and maps, percentage change, unit rates (speed, price per kg) and recipe/mixture scaling — building toward algebraic proportion work used later in MYP 4-5.

Master the unitary method first — find the value of one part, then scale up. Most ratio mistakes come from skipping this step and guessing an operation. Practise mixed-context questions (recipes, maps, money) rather than only bare-number ratio simplification.

To share 360 sweets between Amir and Zara in the ratio 5:4, add the parts (5+4=9), divide the total by 9 (360÷9=40), then multiply each share by its part: Amir gets 5×40=200, Zara gets 4×40=160. Check: 200+160=360.

If 4 workers build a wall in 12 days, how long would 6 workers take? Since more workers means less time, this is inverse proportion: 4×12=48 (total worker-days), then 48÷6=8 days. Check by confirming fewer workers would take longer, not less time.

You're probably losing Criterion D marks for reasoning, not Criterion A marks for calculation. A correct final number with no working, no units, or no explanation of method won't reach the top achievement band — examiners are marking your process as much as your answer.

The calculations themselves are straightforward — it's recognising which type of proportion applies (direct, inverse, or a ratio share) inside an unfamiliar real-world context that trips students up. Most difficulty comes from context-reading, not arithmetic, which is exactly why RevisionPrep drills mixed-context questions rather than isolated ratio sums.

By the end of MYP 3, students should confidently handle multi-step ratio sharing, direct and inverse proportion problems, percentage change, and scale-drawing calculations — laying the foundation for algebraic proportion and similar-triangle ratio work that starts in MYP 4-5.

MYP 1-3 builds the numerical and reasoning foundation; IGCSE and the DP courses (Mathematics: Analysis and Approaches, Mathematics: Applications and Interpretation) apply that same ratio logic to trigonometry, similar figures, rates of change and statistics — so gaps left in MYP ratio work tend to resurface directly in DP-level problems.

Use everyday situations — supermarket unit pricing, recipe scaling, map reading on a road trip — to make ratio reasoning concrete before returning to textbook questions. Ask your child to explain their method aloud; that verbal justification is exactly what Criterion D rewards in class.

Look for practice organised by context type (recipes, maps, rates, mixtures) rather than by pure calculation drills, since MYP assessment is context-heavy. RevisionPrep's MYP Mathematics Topical Worksheets and Revision Notes group ratio and proportion questions this way, with mark-scheme-style solutions showing the reasoning examiners expect.

Yes — a shaky grasp of ratio and proportion in MYP 1-3 tends to resurface as struggles with similar triangles, trigonometric ratios and rates of change in DP Mathematics. It's genuinely worth fixing now rather than patching gaps under exam pressure two or three years later.