GCSE maths marking 2026 decoded: using examiner insight to improve teaching and results

Hello everybody, welcome and thank you so much for joining us today for this GCSE Maths marking decoded webinar. Some quick housekeeping, so if you have any questions during the session, please do pop them in the Q&A box and we'll answer as many as we can at the end, or we'll send out a message later on if we don't have time. Everyone here today will receive the webinar recording along with some exclusive resources including a topic frequency guide, a topic revision list, marking scenario guidance, and some departmental CPD templates, and we'll share all these links with you all at the end. On the way, we'll also mention some of our free GCSE maths resources that you can download from our secondary maths resource library. So for those of you that aren't familiar with Third Space Learning, we provide one-to-one AI maths tutoring for schools, and we've supported thousands of students through their GCSE maths journey. And with all that experience combined with our team's expertise in exam marking, we have shaped today's session. So we've got 30 minutes together, we'll try and make every second count. We are going to cover how GCSE mark schemes really work and some common marking codes that can be misinterpreted, Higher versus Foundation tier expectations and how that can affect your decisions, how to train your maths department to spot critical marking scenarios, some practical exam techniques that you can teach your students to maximize some marks, and at the end we'll do some topic frequency data analysis to help you to allocate revision time effectively. So before we start, let me say hello. My name's Paul. I am the Secondary Curriculum Lead here at Third Space Learning. I'm a former maths teacher myself and a GCSE examiner, and I now oversee all of our secondary maths programmes. I am absolutely delighted to be joined today by Martin, who brings invaluable expertise to this session.

Hi everyone. I've been working with Third Space Learning for about 5 years. Currently I'm helping them Write Their GCSE Tutor Sessions, which are delivered by the AOI tutor Sky. I've also been an Edexcel Product Specialist since 2017. So my experience as both a teacher and examiner sort of gives me an insight into how both sides of the marking process work, and I'm looking forward to sharing that with you today.

Superb. Right, let's dive straight in. So let's start with the fundamentals of the GCSE mark scheme. So mark schemes include different types of marks. So we've got method marks or process marks. We've got accuracy marks, we've got communication marks, alternative methods and special marking codes. There's lots of different things to look at here. So Martin, could you talk us through what teachers really need to understand about these different types of marks?

Absolutely. So there are similarities across all exam boards. Some of the points today will sort of focus on some Pearson Edexcel type mark schemes, such as the process marks, but much of this advice applies across all exam boards. So the important thing about the mark schemes is to understand the special codes. You will have of marks, some which might be dependent on previous marks. There are codes like CAO for correct answer only, where students must get the exact answer with no room for any sort of leeway. There are follow-through marks sometimes, there's special cases, ignore subsequent working. It's important that everyone in your department, whether they're marking mock exams or tests and they're trying to follow that sort of system, that they understand those codes so there's no inconsistency. We've all had those chats in the staff room where someone says, oh, should I give a mark for this or not? If we formalise that through proper department standards and discussions in sort of like meeting times, it will save everyone time. It will also help the students understand why they did or didn't get the marks rather than arguing their case with their teacher and it will better prepare them for the exam. So making sure we understand those marking codes and how marks actually works is essential.

I completely agree. And I mean, that distinction sometimes between the different types of marks, like a process mark and a method mark, can be quite confusing. Would you be able to explain that difference a little bit for us?

Yes, I think the main sort of idea around it is a method mark will want to see something quite specific. There might be alternatives as well that it will suggest. If the question's, you know, it might say you must show your working, and if it says you must show your working and they get the answer right, but you know, they need to show something. If it doesn't say you must show your working, then they can get all the marks. With the process marks, Again, if they get the answer right, they might get the marks. But if it says showing some sort of method, process marks are a bit looser. So there where it could be sort of lots of different ways to approach a problem, they just want to see, you know, a way to start or the next step of their process. It could be like drawing a diagram or listing methods or, you know, listing options. So it won't list every single possible way you could do it. It'll just say, you know, evidence that they've started a process to solve this problem. So, you know, it will just need to be obvious when they're working so they can get that mark if it's required.

That's really, really helpful. Thank you so much. Shall we have a look at an example of this? So we've got a question here that's been answered. Could you talk us through these two different answers and explain to us where the marks would be awarded?

Yeah, so we can see we've got a 4-mark question here to do percentage profit. 3 of those are method marks and there's an accuracy mark. Now neither of these students have got all 4 marks. The first student, Student A, what they've they've got there is they've shown some working out. We can see from the mark scheme that in their first line they have done enough to get— they've got the, the £50, so they've done enough to get those first 2 method marks. And then their second line, getting the £10, gets them the further marks, but they've then just stopped for some reason. So they've got 3 out of 4 marks. Student B has potentially done some working out, maybe in their head or on a calculator, but they haven't written that down and they've just written some other wrong answer down. They've got 20% somewhere, we don't know where, we don't know how, but because they've shown no method for getting that, we cannot give them any marks at all. So it really does highlight the differences between, you know, showing it, not showing it, and how you can get free extra marks if you do.

Gosh, that's so important, isn't it? Like, writing down those method marks, they may pick up marks even if they get the answer wrong in the end. So thinking about the mark scheme then, we'll also want to think about which students should sit the Foundation tier and the Higher tier, and we can build in the mark spec— sorry, the mark scheme expectations to support that decision. This is going to be absolutely crucial for deciding which tier suits your students best. So Foundation tier, we all know, covers grades 1 to 5 and rewards partial method marks quite generously, making them more forgiving for incomplete working, whereas Higher tier, for example, papers, um, they cover grades 4 to 9, they will often require more complex structured solutions. So there are 240 marks across all 3 exam papers, and then that will convert to our final grade. So understanding how these marks convert differently across the different tiers can help us to make strategic decisions about our borderline students. Do you have any top tips, Martin, on how students can decide whether to put borderline students on a Foundation paper or a Higher paper?

So from my experience when I was leading Key Stage 4, we'd always try to analyse what we call those crossover questions for those sort of borderline students. So it's those questions that appear at the end of the Foundation paper and the start of the Higher paper. Could be around about 30 marks. So if a student was able to get the majority of those crossover questions correct and maybe get sort of 20 or 25 out of 30, and again, a lot of that could be from showing their method, we'd say, okay, let's give the Higher Paper a go and see how you perform. If they were losing most of those crossover marks, we'd always say the Foundation Paper was probably a safer option. If you're losing these marks, you're unlikely to pick up many more later on with the much harder content. You might not get in the Grade 4, they might even miss out on the Grade 3. So, you know, the guidance generally is if they're not aiming for a Grade 6, really the Foundation Paper is what they should, they should go for. I think that's always the best, the best thing myself. If a student is aiming for Grade 5 or trying to do Grade 4, the Foundation paper is definitely what they should sit. If they want a Grade 6 or more, then the Higher is what they'll need to do. But it will depend on individual students. So sometimes you might have someone that's just better at picking up those few marks on the Higher paper. If they were to sit the Foundation paper, they might make lots of silly mistakes at the start of that paper on the easy questions, but get some of the later ones right because maybe they're better at tackling those harder questions. So for them, the Higher paper might be their option. So it's important you do lots of practice papers and make sure you're marking those consistently to see, to make sure they're getting all the marks they should be getting.

Absolutely. I mean, those practice papers are absolutely key to GCSE maths success, aren't they? And as luck would have it, we will have a host of practice papers in our secondary resource library, both the Higher and Foundation tiers, also across Edexcel, AQA, and OCR. And in fact, we are releasing a brand new set of papers for 2026, end of February, start of March, for the new exam season. So well worth a look. Have a scan of this code and you'll go straight to the website to download those papers. Right, so thinking now about mark scheme application, you're absolutely right, it can really depend on how teachers can apply these mark schemes quite differently. So some may well undercredit marks, uh, or some might overcredit marks. So these inconsistencies across the department are going to really skew that data and can affect what your students may or may not need to focus on. So we want to align marking standards across the department. That's absolutely vital. In your experience, Martin, leading this work, would you say there are some best techniques that department heads can use to standardise marking across their busy teams?

So really, if you've got any exam markers who have had the official training in your department, they should be available to offer the advice to less experienced teachers. Um, those conversations you're having in the staffrooms need to be made more formal, perhaps in sort of departmental meetings, inset days, things like that. Definitely have some CPD sessions on that. What you don't want is one teacher giving a mark to a student in one class and then another teacher having a student with the exact same work and wrong answer, but then giving different marks. The students will start to complain, they'll argue their point, they'll compare things. The teachers won't know what to do. It creates this unnecessary friction you just don't need. So we need to make sure we're collaborating. And if there's any teachers that have had that marking training, they should lead this departmental session to say, okay, this is what we need to do if we see this. You could come up with scenarios for questions that could be awkward to mark, you know, share them around, do some live marking, things like that. When you're doing it properly for the exam board, you still will have heated debates with your team leader about why I didn't accept your mark for a particular question. It does happen sometimes, and it still happens even with the really experienced people. So Throughout the marking process, you could still also get a message from the team leaders and the senior people saying, we've seen what you're consistently seeing in this question. Everyone needs to stop what they're doing for that question now, read this information. If you see this particular thing, you give that mark. So it is important that that happens on a smaller department scale as well.

Yeah, absolutely. I mean, one practical way to do this would be just to get your whole team together and just look through some past paper questions. So go through them together and make sure everybody in the team's on the same page. You're going to find some examples of these GCC maths mark, GCSE questions in our maths marking decoder, both blank and completed example questions which you can use with your team, and we'll email that out at the end for you. So speaking of using examples with your team, let's discuss now training your team to spot particular scenarios that often trip students up. Martin, can you talk us through these?

So yeah, there's several key areas where students commonly lose marks and the examiners will see repeatedly. So first, rounding too early in calculations. 'cause some of these accuracy marks, they may have a particular interval of range that need to be in or might round to something, you know, particular. So if they round too early, they can lose those accuracy marks, even if their methods are correct. So try to make sure they keep their decimal places in the calculator until the very, very final answer. Second one, contradictory working. So if a student shows two different methods that give two different answers and have not made it clear which answer they want to provide as their sort solution, you need to make sure you're marking the one that gives the least number of marks. You can't give them the benefit of doubt. You've got to make sure that you've given the least. There is an answer line and you need to try to make sure that you're telling students to use that answer line to make which answer they want to use and make it clear to them. Next one is like misreads. So misreading numbers and miscopying them down. If a student reads 814 as 841, then maybe they might write it down wrong. They could still get the method marks if their working is correct based on what they read and what they wrote down, but they will probably lose the action marks. So in the GCSE marking process, normally misreads are passed on to team leaders to confirm what to do with those. Finally, crossed out work. So if a student has tried something out and they've crossed it out and then they've not replaced it, you still need to mark it, okay? If you can read it, mark it, because there could be something in there that you can make out that is worth a mark. So tell your students to not go mad with crossing things out, just put a few lines through it. And, you know, if they're not sure, they can move on, tell them it will be marked. Just make sure the examiner can see it.

These are really brilliant practical points. Should we have a look at how this might work in practice? So what we've got here is a really typical simplifying indices expression question. We've got 3 different responses and let's walk through how we'd apply the mark scheme to each of these 3 different students. So let's look at the first one. So there's our mark scheme, and this is what the student's done.

So the first one here, we can see that the method mark— it's only 2 marks, this question— the method mark has got some different options of how you can give this method mark. So this student has shown their clear working out, okay? We can see that the answer they're given is not what the answer is, so they've given an answer of 3, which is incorrect. But can we give them a method mark? So they've shown on their first line that 3 is the minus 2 times 3 to the 5 is 3 cubed. That is one of the things that give them a method mark, so we can give them that. Okay, but because they're getting the wrong answer, they cannot get the accuracy mark. So the next person, we can see they've got a similar sort of line. They've got 9 divided by 3 equals 3 like the person before, but they didn't show that previous working out. Out. So we don't know where that came from. Okay, so it's incorrect working out. We cannot, we cannot give anything for that. And the answer is still wrong. Therefore, this student will not get an F mark or the accuracy mark. The last one, again, we can see that the answer is on there, on the answer line, which is 9, and that is correct. But we can't just then give them the 2 marks because we have to be very, very careful that they haven't got that from incorrect incorrect working. And we can see that there is some incorrect work in there. We've got this 9 to the power of 3 instead. We don't know exactly, we can't just like assume that they're doing something particular. We just have to go by what we can see and there's some incorrect work in there. Therefore, we should say, right, no, something's wrong. They've got that, therefore we shouldn't give them any marks. So it's really important that they show a clear structure if they're working out and they do not have some random incorrect work in there that they might want to disregard if they do cross it out and move on.

So interesting, isn't it? I mean, these are exactly the kind of scenarios that teachers should be going through and discussing in those departmental meetings to ensure that consistency. Um, okay, so we've had a look at training your department for marking for consistency to improve GCSE grades. Let's move on and let's have a look at some strategies that teachers should be explicitly teaching to students. So these aren't just good practice, these are mark-winning techniques. So let's start with strategy 1. So this is show your full working. So this is going to build structured logical thinking and promote clarity. So I always used to say to students, show the examiner what you know. Make it very, very clear, very ordered. Make it easy for them to give you marks. Don't keep calculations in your head. If you know something, get it on the page. There may be method marks available even if the final answer ends up being wrong.

So strategy 2, setting up equations and diagrams. So specifically for Edexcel, for those process marks, it could come from a diagram. So, you know, a little diagram, rectangles, bar models, things like that. If it's clear what they're representing, you could give them that process mark. So if students are writing equations and showing diagrams, you know, it's really important they do that to help secure as many method marks as possible.

Hey, number 3. So let's highlight key information in questions. So this is going to strengthen critical reading skills, help students filter out the general noise, and help them to really focus on the key information that's needed for the question. So it's going to encourage that attention to detail and improve their task prioritisation within a longer question.

Number 4, ensure the final answer is in that required form. So we know that Some exam papers like Pearson will sometimes ask, give you answers to 3 figures, and we know for most of them that doesn't actually matter that much if the question is not about rounding, but there are times when the question is about rounding and they might want it in a, you know, around this answer to a certain amount, or it might want something in exact form, could be in surge form, could be in terms of pi. It's important the students do that. So make sure they are reading the instructions carefully and writing their answers in the correct form, otherwise they are going to lose some accuracy marks.

Absolutely. Number 5: annotate. Annotate, annotate, annotate. Annotate diagrams, annotate graphs, annotate charts. If a student knows something, encourage them to write it on the diagram. I mean, this is absolutely crucial for angle questions, geometry problems, circle theorems. The information on the diagram is available to marks. So even if a student hasn't included something in their calculation but they've written it on the diagram, they can be awarded marks for it.

Definitely. So like I always found when I was teaching angle questions, whether it was parallel line questions or circle theorems, I would just tell students to do everything around the diagram, put things on the diagram like little squares for right angles, have arrows with the reasons pointing to, you know, whatever angle they found, write the reason next to it where I point to it to make it obvious because sometimes I found it hard to use that special notation like angle AOB later on you know, lower down on the paper. So put it next to a diagram, point to it, it's perfectly acceptable and it will be marked. The last one, checking units and conversions. So if the question has got units in it and it's not written on the answer line, make sure the students write that down because that's normally going to be worth a mark. If it's got— if the units are there, they need to make sure that their answer suits that unit. So if it's got to be in centimeters and it's like the length of a pencil and they're working out the answer is 0. 0.0000084, then there's probably something wrong there. They might have done something in a different unit and haven't converted it, you know, properly. So make sure that their answer makes sense. Logical thinking really matters there.

I mean, these strategies are just so, so important, and in fact, they're so important that we have created a GCSE exam strategies poster that covers all these points. You can download it from this QR code on the screen now. It's also on the secondary resource library, and you can just print it off, display it in your classroom. So if a student gets a bit stuck, you can direct them to it as a quick referencing guide. And actually, one of the challenges teachers often mention is finding time to teach these strategies explicitly to every student who needs them. I mean, especially when you've got 30 different students in a class all at different stages. So that is one of the reasons that we at ThirdSpace have created our wonderful AI Math Tutor Sky. It's for targeted GCSE revision, so every Sky session explicitly models these exam techniques, showing working, checking answers, using efficient methods. And because it's one-to-one, each student gets personalized support on exactly which techniques they need the most. So for example, if a student consistently forgets to include units or rounds a bit too early, Sky can pick that up and address it directly in future sessions. It means that these exam habits get reinforced regularly without adding to your busy workloads. So beyond now these core strategies, there are some specific exam techniques that we want to just highlight specifically. So Martin and I are going to ping back and forth with this. All right, so number 1, strategic pacing. So this is crucial. Part of the skill is getting through the exam paper within the time limit. So as a rough guide, we recommend about 1 mark per minute to give a bit of time at the for checking, but it's key not to panic. If your students are still on a 1 marker or a 2 marker after a few minutes, encourage them to move on. They can always come back. If they're on a 3 or 4 marker and really struggling, encourage them to write down what they know and then move on. They might pick up 1 or 2 method marks and they can always return to it later. So message is: keep calm, do a few more questions, and then come back back with fresh eyes.

So the second one is decoding command words. So every example will use roughly the same command words throughout the papers. So make sure your students know what they mean. So write down, state, these are normally those one-mark questions, fairly quick, straightforward. Work out, find, calculate normally involve working out with method marks and then an accuracy mark. So students need to be aware when a question needs more detail. So make sure they write enough for the number of marks available.

Absolutely. Number 3: sense check the answer. Is my answer sensible? So areas and volumes should be positive. If their answer is negative, something's gone wrong. A recipe is unlikely to call for 700,000 kilograms of flour. So students should look at their answer and go, is this relevant? Is this sensible? And if it's not, take another look. It's possible a conversion's gone wrong or there's been a small calculation error. An error, and that simple check can be the difference between the accuracy mark being awarded and them losing it.

The fourth one is never leave blanks. Examiners are going to be overjoyed if they see a blank question because they can just give it a zero and move on. So we need to make them work for it. Okay, so make them actually look for something on that page, even if it's crossed out. So check for something. Yeah, it's important. So write something down. There could be method mark available even if your answer is Number 5: okay, use your calculator.

I mean, this sounds really obvious, but for calculator papers, students should actually use the calculator. Make sure that they are really familiar with their calculator, and ideally they should have their own that they use throughout Year 10 and Year 11 and get— really get to know it, so they're not borrowing different types of calculators. Encourage them to write down what the calculation is— there's your method mark— then type it into the calculator, and then write it on the answer line. Do not try and do long multiplication on the calculator paper. It is heartbreaking when we see this and they make an error and they lose the accuracy mark. It's going to waste time. It's going to create opportunities for errors. Don't do it. Write the calculation down, put it in the calculator, and write down the answer.

And yeah, linking with that one there, finally, substituting correctly into a formula. So if the student needs to use a formula where it's from the formula book or not, if they write the formula down and then substitute their values into that formula correctly, that can be worth a method mark. If it's one that's given to them, just subject numbers incorrectly generally is a method mark. So make sure they do that. Once they've done that, they can simplify things and then proceed. If they've done that though, there should be method marks available, even if they may make a calculation error later and then get the wrong answer. So importantly, they get that skill sorted out and it will be really, you know, showing loads of working is really good to do that.

Yeah, and we have a formula sheet that students can use, so download it with this QR code, or again, it's all on the Secondary Resource Library. I cannot recommend that enough. There's so much stuff on there, and it's all free, ready for you to download. Right, we have covered a lot of ground. So we've looked at understanding mark schemes, training techniques, student strategies, but how do we actually embed this across a busy department in a sustainable way? So let's just take a quick look at a couple of scenarios. So Martin, do you want to take us through the first one.

Yeah, so you might decide in your department that they'll be saying, okay, we're going to require all of our students to show working all the time, you know, and if they don't, we're not going to give them full marks. Okay, we want them to get used to doing this. So we're going to say, okay, we're making consistent across the department. We're going to make sure it's communicated with the students and the parents. So everyone understands it and then don't complain about it. And you make sure you're saying this is for their benefit. To get them used to showing all the work in the exam to gain as many marks as possible. You can even edit the papers for every question that says all working must be shown. Okay, so then you'll have a more consistent marking throughout all those tests. And then, you know, the teachers that would normally just give full marks for correct answer will have to be forced to be looking for working out and making sure they're doing it. It'll, you know, it'll be consistent and that's the key word.

Absolutely. Let's have a look at another scenario. So another way to embed that consistency would be to practice marking questions where multiple methods have been displayed on the question. So for example, a question might have been answered with two complete methods and it's not clear which method the student intended. So we remember that both methods have to be marked in full and then the method with the lowest number of marks is the one that's awarded. So A great takeaway for your departments here is to insist that students make it super clear which method they want the examiner to mark. It is so upsetting when a student has a fully correct method, got cold feet, done something else, and then we have to mark the second one because it's contra— because it's the lowest number of marks and it contradicts what they've already written. So we want to make sure that everyone's super clear, that make it clear which which method the student wants the examiner to mark. In our GCC Maths marking guide, you'll find these scenarios and loads and loads and loads and loads more. You might want to use these to create policies around things such as requiring full working, how to handle misreads, and a ton of other tricky situations. Well worth a look. And again, QR code here if you want to go to it straight away. Right, finally, before we wrap up, Let's quickly talk about using some data strategically. So once you've spent time with the departments and have agreed a consistent approach to marking, the next stage is to let your students practice their skills with some mock exams and then give your departments the chance to practice their skills with marking those mock exams. Martin, what should we be looking out for here? Can you give us an example?

Yeah, so after marking mocks using the mark schemes, look for consistent patterns, look for topics that, you know, your students are constantly losing marks. Are those errors due to content gaps or exam technique? You know, you can identify misconceptions mark schemes rather than broad topic weaknesses. So use those mark schemes to show your students what the examiners credit and what they don't. And then you can use that data to provide lots of practice on high-value questions. So, you know, see where they can gain lots of marks.

And to help you with this, our team at Third Space Learning has gone through all the exam papers from 2017 right through to 2025 and conducted some deep analysis. Martin, could you very quickly just give us a very brief overview of this?

Yeah, so looking inside the sort of the main content strands, uh, which see what topics actually come up. Yeah, you can use that as part of your revision plan. So, you know, when I start revision, I'd go and say, okay, lots of questions on addition and subtraction, those multiplication and division, and look for the, you know, the ones where that's going to be really, really beneficial for the broader topics. So it might be easier to do that than more beneficial to group questions by a specific skill. So the message here is to don't just use Frixion's data as a guarantee that something's going to, you know, will or won't come up. Just because it came up one year doesn't mean it's going to come up again, but you can look, use it to look for patterns and make informed decisions about what to focus your time on.

Yeah, exactly. So we can combine the insights from your own marking analysis with this multi-year topic frequency data to support your students to tackle particular areas of weakness, and that will maximise their opportunities to gain marks in the exam. All this data and so much more, along with our analysis methodology, is included in the full resource pack that you'll get at the end of the webinar. Wow, look at that, 30 minutes exactly, Martin. Thank you so much everyone for joining us today to help us to demystify GCSE maths marking. We hope you found it useful and you can take something away that's practical that you can try with your departments next week. All the resources we mentioned today are available through this lovely QR code on screen, We got mark scheme code examples and explanations, departmental templates for standardising that marking, marking guide scenarios, GCSE marking strategies, those free maths papers that, um, following the exact formula of the exam. Um, remember, new ones are coming out at the end of February, start of March, and that topic frequency analysis deep dive data. This will all be emailed to you after the session. And as I mentioned before, we've got hundreds, thousands of free GCSE resources on the secondary resource library. Do have a look on there, they are an incredible resource and they're all free. And if you're interested in hearing more about our wonderful Sky, the AI maths tutor that delivers personalized one-to-one GCSE revision, do get in touch. We would love to hear from you at hello@birdsplacelearning.com or register your interest online on the website. Our team will be delighted to arrange a free demo session so you can see Sky in action and see what we're so excited about. Martin, thank you so much for sharing your expertise today. It has been absolutely fascinating.

Yeah, thanks again everyone for joining us. We know how busy you are this time of year, so really appreciate you taking time to join us today.

Best of luck everyone with the GCSE season. We hope these strategies are useful for you. Please do reach out to us if we can help in any way, and thank you for joining us.