How GCSE Maths Is Marked: Why Your Working Is Worth More Than the Answer

Maths feels like the most objective subject to be marked in: an answer is right or it is wrong. That is exactly why students lose marks they should keep. Because they assume the final number is all that counts, they do calculations in their head, cross out working, and treat the answer line as the whole question. GCSE Maths is marked far more generously than that — but only for students who show what they did. The marks are spread through the working, and the ones who write it down collect them even when the final answer slips.

Method marks and accuracy marks

Maths mark schemes split marks into method marks (M) for using a correct process and accuracy marks (A) for the correct value. A four-mark problem might be three method marks and one accuracy mark, which means most of the marks are available before you reach the final number. A student who writes the correct method and makes an arithmetic slip at the end still scores highly; a student who writes only a wrong answer scores nothing. This is the heart of how method marks work, and in maths it is worth more marks than in any other subject.

Show every step — and never cross out working

The instruction “you must show your working” is not about neatness. It is the examiner telling you where the marks are. Two disciplines protect them:

• Write each stage down. Mental arithmetic that goes wrong leaves nothing to award method marks against. Even an intermediate value the examiner can follow is worth marks.
• Do not cross out working unless you are replacing it. Crossed-out work is not marked, so a panicked student who scribbles out a correct method has deleted their own marks. If you are unsure, leave it.

Error carried forward

Multi-step questions reward you even after a mistake. Under error carried forward, if you make a slip early and then use your own wrong value correctly in the next step, the examiner can award the later method marks as if the earlier value had been right. It only works if the working is visible — the examiner has to be able to follow your wrong number through. A student who hides the steps forfeits it entirely.

“Show that”, “prove”, and reading the question

Maths has its own command words, and they change what a full answer looks like. “Work out” wants the value with working. “Show that” gives you the answer and asks for the reasoning that reaches it — so writing the answer down earns nothing; the marks are entirely in the steps. “Prove” wants a watertight chain of logic, not an example. Knowing which you are facing is the same habit that matters across every subject — see command words.

Units, accuracy and the final mark

As in physics, a separate mark is often reserved for the correct unit — pounds, cm², m/s — and rounding to the degree of accuracy the question asks for. Giving an answer to the wrong number of decimal places, or leaving off “cm”, can drop the accuracy mark on an otherwise perfect solution. Read the last line of the question: it usually tells you the units and the accuracy it wants.

Board differences, and why practice is what fixes this

The mathematics is common across boards, but the style of the papers, the balance of the topics and the exact wording each mark scheme rewards differ between AQA and Edexcel. None of the habits above are about knowing more maths — they are about laying working out so the marks you have earned actually count, and that only becomes automatic with practice on real questions where you see, mark by mark, what your solution scored. On Exaim every answer is marked against the board’s scheme, point by point, so a lost method mark shows up as exactly that — a fixable habit, not a topic to re-learn. See AQA GCSE Maths or Edexcel GCSE Maths.