How Cambridge Marks IGCSE Maths: What Parents Should Know

How Cambridge Marks IGCSE Maths

Understanding how Cambridge awards marks transforms how students approach their exam. Many students believe that getting the right answer is what earns marks. In IGCSE maths, this is only partially true.

The Mark Scheme Structure

Cambridge’s mark scheme uses specific mark types:

• M marks (method marks): Awarded for using the correct mathematical method, even if the final answer is wrong due to an arithmetic error. These marks are only available if working is shown.
• A marks (accuracy marks): Awarded for the correct answer. Usually dependent on the preceding M mark having been earned.
• B marks (independent marks): Awarded for a specific correct value or statement, independent of method.
• ft marks (follow-through marks): Awarded when a student carries an earlier wrong answer through correctly into subsequent parts. These marks reward correct process even when a previous error has been made.

The Practical Consequence: Always Show Working

A question worth 4 marks might be structured as [M1, M1, A1, A1] — two method marks and two accuracy marks. A student who writes the wrong final answer but shows correct working can still earn 2 or 3 of those 4 marks.

A student who writes the correct final answer without any working earns only the A marks — often 1 mark out of 4 for a multi-step question.

This is why Teacher Rig insists on working shown from the first session. It is not a stylistic preference — it is directly tied to the number of marks awarded.

Geometry: Reasons Are Mandatory

For circle theorem questions, angle-in-polygon questions, and similar geometry proofs, Cambridge requires not just the correct angle but the full name of the theorem. A student who writes “angle = 38°” without writing “angles in a semicircle” (or the relevant theorem) will lose marks even though their answer is correct.

What “Consequential Marks” Mean for Your Child

If your child makes an error in part (a) of a question and carries that error through to parts (b) and (c), they can still earn full marks on (b) and (c) if their subsequent working is correct. This is Cambridge’s follow-through policy, and it means that persevering through a question — even after making an error — almost always earns more marks than leaving subsequent parts blank.

How Teacher Rig Teaches This

From the first session, Teacher Rig trains students to:

1. Always write at least one line of working per method step
2. State geometry theorem names in full
3. Never leave a question blank — always attempt partial credit
4. Check whether parts (b) and (c) use the answer from (a) — and if so, substitute carefully

Book a free trial — Teacher Rig will show your child exactly how the mark scheme works on a real past paper question in the first session.