What Mistakes Do Younger MYP Maths Students Make?

The most common mistakes are skipping working steps, misreading command terms like 'justify' or 'investigate', rushing arithmetic under time pressure, and forgetting units or labels. None of these are ability problems — they're habits, and every one is fixable with deliberate practice before your next assessment.

Because MYP Maths marks the thinking, not just the number. Criterion B (Investigating Patterns) and Criterion C (Communicating) both require visible reasoning, not a correct final line. A right answer with no working can score full marks on Criterion A but very little elsewhere.

Because the four criteria assess completely different skills, not just 'getting maths right'. Students often assume one strong test answer covers everything, when Criterion A rewards knowledge, B rewards investigating, C rewards communication and D rewards real-world application — each graded separately, out of 8.

Yes — rounding too early, misreading fraction or negative-number displays, and trusting the calculator without estimating first are frequent causes of lost marks. A wrong final answer from a correct method usually still scores well on process criteria, but calculator slips waste time you could use checking work.

Write every step as a full mathematical sentence, not scattered numbers — show the setup, the operation, and the conclusion in words or symbols. Markers can only credit reasoning they can actually see on the page, so a tidy three-line solution beats a correct answer with no trail.

Slow down at the exact moments you're most likely to slip: negative signs, fraction operations, and order of operations. Estimate your answer before calculating — if you expect roughly 40 and get 4, you'll catch the error immediately instead of submitting it unchecked.

Re-read the command term first — 'calculate' just wants a number, but 'justify' or 'explain' needs reasoning in words too. Then substitute your answer back into the original problem to confirm it works, rather than just re-reading your own working, which your brain tends to skim past.

Criterion A assesses knowledge and understanding, B assesses investigating patterns, C assesses communicating, and D assesses applying maths in real-life contexts. Each is marked out of 8 using its own achievement-level descriptors, so strong marks on one criterion never guarantee strong marks on another.

Tests mainly assess Criterion A under time pressure. Investigations assess Criterion B and often C and D too, rewarding a stated pattern, a tested conjecture, and a clear conclusion — not just a correct table of values. Students who treat investigations like a test tend to lose marks on the reasoning stages.

The biggest one is stopping after finding a numerical pattern without stating it as a general rule, formula, or conjecture. Others include not testing whether the rule works for a new value, and writing a conclusion that just repeats the numbers instead of explaining what they mean.

Ask to see the working, not just the final answer — that's exactly what MYP criteria reward. Encourage your child to explain a solution out loud; if they can't explain why a step works, that's usually the gap a teacher will also mark down, and it's worth revisiting before the next assessment.

Yes, entirely normal — MYP 1-3 is where students first learn to show mathematical reasoning formally, not just produce answers. The mistakes above are the same ones I've seen in first-year MYP scripts for years; what matters is whether they're still happening by the end of MYP 3, not whether they happen at all.

Targeted, criterion-aligned practice works better than generic revision — your child needs to see what a full-marks Criterion B or C response actually looks like, not just more questions. Revision Notes and Topical Worksheets on revisionprep.com are built around the MYP criteria, showing worked examples alongside the practice questions.