A-Level Maths exam technique: how to stop losing marks you deserve

Most of the marks students lose in A-Level Maths are not lost to topics they cannot do. They are lost to habits: working that is too thin to earn method marks, answers that do not quite answer the question, one awkward question that eats fifteen minutes, and no time left at the end to check anything. All of these can be trained out in a few weeks of timed practice, and for a student sitting on the edge of a grade boundary it is usually the quickest improvement available. Here is what I teach, and why.

Method marks are the cheapest marks on the paper

Edexcel’s own marking guidance explains the system plainly. M marks are for knowing a method and attempting to apply it. A marks are for accuracy, but they are only available if the relevant M mark has been earned first. B marks are independent accuracy marks. The practical consequence is that an answer with a slip in the arithmetic can still collect most of a question’s marks, provided the method is visible, while a bare wrong answer collects none.

The same guidance says that on one- and two-mark questions a correct answer may be enough to imply the method, but that longer questions need enough working to reveal it. So the rule I give students is simple: on anything worth three marks or more, write the line that shows what you are doing before you reach for the calculator. Write the equation you are solving. Write the formula you are substituting into. Write the derivative before you set it to zero. It costs you a few seconds, and it is the difference between losing one accuracy mark and losing the lot.

A related habit is worth dropping. Students rub out half-finished attempts the moment they doubt them. Unless you have a better attempt ready to replace it, leave it. A method that is going somewhere, even if you suspect it is wrong, can still be earning marks.

Know when “show that” and “use algebra” take your calculator away

Pearson’s guidance is clear that you may always use a calculator to check an answer, but you should still write down the equation you solved. It also says that phrases such as “use algebra to”, “show that” and “prove that” mean the calculator is not an acceptable route, and that a bold statement saying solutions relying entirely on calculator technology are not acceptable means exactly that. On “show that” and “prove” questions, every step has to appear on the page, because the answer is already printed and the working is all there is to mark.

The opposite error is just as common. Students who have trained themselves to show everything solve a plain quadratic by hand, line by line, when the wording permits a calculator, and then run short of time on the last questions. Read the command words before you start, and decide which kind of question you are looking at.

Answer the question that was asked

A surprising share of dropped marks are small, careless and entirely avoidable. Label every part of a multi-part question, because working written under one part may only be credited to that part. Give the answer in the form requested: exact when it says exact, to a stated degree of accuracy when it gives one. In mechanics, Pearson’s guidance says to use g = 9.8 unless told otherwise and to give answers to two or three significant figures; it notes that over-accurate answers can be penalised, which surprises almost everyone the first time they hear it.

Context matters too. A hypothesis test that ends with “reject H0” and no sentence about what that means for the situation in the question has not finished the job, and a modelling question usually wants a comment on the model, not another number. Before leaving any question, read its last line once more and check that what you wrote is what it asked for.

Triage: 72 seconds per mark

Every A-Level Maths paper is two hours for 100 marks, so you have roughly 72 seconds per mark. A four-mark question should take about five minutes, and a nine-mark problem-solving question about eleven. These are not targets to hit exactly, but they tell you when you are in trouble: if you have spent ten minutes on a four-marker, the question is no longer worth what you are paying for it.

The assessment objectives point the same way. Half the marks on every paper are for standard techniques, a quarter for reasoning and proof, and a quarter for problem solving. The standard-technique marks are the ones that should be banked first and banked cleanly. My approach is a first pass through the paper that answers everything you can see your way through, with a clear mark in the margin against anything you skip, then a second pass that goes back to the skipped questions with whatever time remains. Leaving a hard question is not giving up on it. It is deciding when to pay for it.

One warning from long experience: do not skip a question and forget to return. Students who skip several questions without marking them often finish the paper convinced they have answered everything.

The check-back protocol

Plan to finish your first pass with ten to fifteen minutes in hand, and spend them on a fixed routine rather than a vague reread. Rereading your own working mostly shows you what you meant, not what you wrote, so the checks should test the answer from a different direction.

• Sense-check each answer. Probabilities between 0 and 1, lengths and times positive, an angle that fits the diagram, a speed that a real object could have.
• Substitute back. For any equation you solved, put the answer in. It takes a few seconds and catches sign slips that rereading never will.
• Re-read the last line of each question. Check the form, the accuracy, the units, and whether you were asked for the value, the coordinates or the equation.
• Check the marks against the effort. A five-mark answer that took three lines deserves another look.

None of this works if you have never rehearsed it. A check-back routine you meet for the first time in the real exam will not survive the pressure, so build it into every timed paper you do, and finish early on purpose.

How to train it

Technique improves through marking, not through more questions. When you mark a practice paper, sort every lost mark into one of two piles: marks you lost because you did not know how to do it, and marks you lost for any other reason, such as thin working, wrong form, a misread question or a slip you would have caught. In my experience the second pile is larger than students expect, and it is the cheaper one to fix. My guide to using past papers properly sets out the marking and error-log routine, and the ten most common A-Level Maths mistakes lists the recurring errors that will probably appear in that second pile.

It is also worth knowing how little separates one grade from the next. Grade boundaries move every summer, and a handful of marks can be the whole gap between adjacent grades, as the figures in my piece on how grade boundaries are set show. Marks recovered from technique alone count exactly as much as marks won from new content. If you would like to see what clean written solutions look like, the worked past-paper walkthroughs on my videos page are laid out the way I want students to write them.