Number Operations and Applications
MYP Year 2 Mathematics — Number Operations and Applications
Every calculation you'll ever do in maths rests on one quiet agreement: everyone evaluates an expression in the same order. This chapter is really about that agreement — BODMAS/PEMDAS — and then about applying it honestly to whole numbers, decimals, fractions and real contexts where a wrong order doesn't just cost a mark, it costs a customer the wrong bill or a warehouse the wrong shelf plan.
Overview — How the Chapter Fits Together
Number operations only feel 'easy' when the order is unambiguous. The moment brackets, powers, and mixed operations appear together, the convention you follow determines the answer — which is exactly why examiners keep asking you to 'show all steps': they're checking you followed the convention, not just that you can multiply.
- BODMAS (UK/IB-common) and PEMDAS (US) name the same four-tier hierarchy — they only disagree on which letter comes first, never on what actually happens first.
- Whole numbers, decimals and fractions all obey BODMAS identically — the operations just look different (place value vs. common denominators).
- Divisibility and remainders sit underneath everything: knowing a number is divisible by 3 or 9 instantly speeds up simplifying fractions later in the chapter.
- Word problems and real-world tasks are where marks are actually lost — not because the arithmetic is hard, but because the translation from English to expression goes wrong before BODMAS even gets applied.
The shape of the chapter
Command terms you'll actually meet in this chapter
| Command term | What it demands | AO | Mark-earning move |
|---|---|---|---|
| Calculate | Obtain a numerical answer, showing the relevant stages of working. | AO2 | Method marks are given per correct step — a bald final answer with no working can lose every method mark even if it's right. |
| State | Give a short answer with no explanation or working required. | AO1 | One mark for the correct fact; extra working neither helps nor hurts here. |
| Show (that) | Give structured, logical steps that clearly justify a stated result. | AO2 | Every intermediate line must actually appear on paper — skipping the bracket step loses a mark even when the final total is correct. |
| Explain | Give a reason or mechanism, not just a restatement of the rule. | AO3 | Naming BODMAS without saying why the order removes ambiguity scores 0 out of the mark. |
| Identify | Select or name the correct item from what's given. | AO1 | No working expected — just the correct choice, e.g. which operation happens first. |
| Describe | Give a detailed account that uses the specific terms the question names. | AO2 | Q8-style questions ask you to use the exact words brackets, orders, division/multiplication, addition/subtraction — missing any one of these named terms costs a mark, even if your final number is correct. |
Key point
Overview